Sporadical "Kernel panic - not syncing: Attempted to kill init!"

Hi to all,
I'm using a SBC8100 board (the same of devkit8000), kernel
Linux-2.6.29-rc3-omap1, but sporadically, more or less one time on
ten, boot process stops just after mounting ubifs, and prompt me
"Kernel panic - not syncing: Attempted to kill init!"

The very strang thing is that, as I said, the problem happens just
sporadically and the most of times all works fine.
Please, someone has ideas?

Thanks to all in advance

In the following the complete log:

NAND read: device 0 offset 0x280000, size 0x300000
3145728 bytes read: OK
## Booting kernel from Legacy Image at 80300000 ...
   Image Name: Linux-2.6.29-rc3-omap1
   Image Type: ARM Linux Kernel Image (uncompressed)
   Data Size: 2178760 Bytes = 2.1 MB
   Load Address: 80008000
   Entry Point: 80008000
   Verifying Checksum ... OK
   Loading Kernel Image ... OK
Using machid 0x7d2 from environment

Starting kernel ...

done, booting the kernel.
Linux version 2.6.29-rc3-omap1 (fabiano@merlino) (gcc version 4.4.1
(Sourcery G++ Lite 2010q1-202) ) #10 Thu Apr 28 14:21:19 CEST 2011
CPU: ARMv7 Processor [411fc083] revision 3 (ARMv7), cr=10c5387f
CPU: VIPT nonaliasing data cache, VIPT nonaliasing instruction cache
Machine: OMAP3 SBC8100
Ignoring unrecognised tag 0x54410008
Memory policy: ECC disabled, Data cache writeback
OMAP3530 ES3.1 (full speed SGX, IVA2)
SRAM: Mapped pa 0x40200000 to va 0xd7000000 size: 0x100000
Built 1 zonelists in Zone order, mobility grouping on. Total pages:
Kernel command line: console=ttyS2,115200n8 ubi.mtd=4
root=ubi0:beagleboard-rootfs rootfstype=ubifs rootwait
Clocking rate (Crystal/DPLL/MPU core): 26.0/266/500 MHz
IVA2 clocking rate: 360 MHz
Reprogramming SDRC
dpll3_m2_clk rate change failed: -22
GPMC revision 5.0
IRQ: Found an INTC at 0xd8200000 (revision 4.0) with 96 interrupts
Total of 96 interrupts on 1 active controller
OMAP34xx GPIO hardware version 2.5
PID hash table entries: 1024 (order: 10, 4096 bytes)
OMAP clockevent source: GPTIMER1 at 32768 Hz
Console: colour dummy device 80x30
Dentry cache hash table entries: 32768 (order: 5, 131072 bytes)
Inode-cache hash table entries: 16384 (order: 4, 65536 bytes)
Memory: 128MB 128MB = 256MB total
Memory: 255104KB available (4016K code, 369K data, 164K init)
Calibrating delay loop... 499.92 BogoMIPS (lpj=1949696)
Mount-cache hash table entries: 512
CPU: Testing write buffer coherency: ok
net_namespace: 520 bytes
NET: Registered protocol family 16
omap3evmdc: Driver registration complete
OMAP DMA hardware revision 4.0
USB: No board-specific platform config found
OMAP DSS rev 2.0
OMAP DISPC rev 3.0
OMAP DSI rev 1.0
bio: create slab <bio-0> at 0
i2c_omap i2c_omap.1: bus 1 rev3.12 at 2600 kHz
twl4030: PIH (irq 7) chaining IRQs 368..375
twl4030: power (irq 373) chaining IRQs 376..383
twl4030: gpio (irq 368) chaining IRQs 384..401
i2c_omap i2c_omap.2: bus 2 rev3.12 at 400 kHz
i2c_omap i2c_omap.3: bus 3 rev3.12 at 400 kHz
SCSI subsystem initialized
twl4030_usb twl4030_usb: Initialized TWL4030 USB module
usbcore: registered new interface driver usbfs
usbcore: registered new interface driver hub
usbcore: registered new device driver usb
musb_hdrc: version 6.0, musb-dma, peripheral, debug=0
musb_hdrc: USB Peripheral mode controller at d80ab000 using DMA, IRQ
NET: Registered protocol family 2
IP route cache hash table entries: 2048 (order: 1, 8192 bytes)
TCP established hash table entries: 8192 (order: 4, 65536 bytes)
TCP bind hash table entries: 8192 (order: 3, 32768 bytes)
TCP: Hash tables configured (established 8192 bind 8192)
TCP reno registered
NET: Registered protocol family 1
OMAP35x Linux PSP version (OMAP3EVM)
NetWinder Floating Point Emulator V0.97 (double precision)
VFS: Disk quotas dquot_6.5.2
Dquot-cache hash table entries: 1024 (order 0, 4096 bytes)
JFFS2 version 2.2. (NAND) © 2001-2006 Red Hat, Inc.
msgmni has been set to 498
alg: No test for stdrng (krng)
io scheduler noop registered
io scheduler anticipatory registered (default)
io scheduler deadline registered
io scheduler cfq registered
Generic Backlight Driver Initialized.
Serial: 8250/16550 driver, 4 ports, IRQ sharing enabled
serial8250.0: ttyS0 at MMIO 0x4806a000 (irq = 72) is a ST16654
serial8250.0: ttyS1 at MMIO 0x4806c000 (irq = 73) is a ST16654
serial8250.0: ttyS2 at MMIO 0x49020000 (irq = 74) is a ST16654
console [ttyS2] enabled
brd: module loaded
loop: module loaded
dm9000 Ethernet Driver, V1.31
eth0 (dm9000): not using net_device_ops yet
eth0: dm9000e at d08b2000,d08b6400 IRQ 185 MAC: 00:11:22:33:44:55
Linux video capture interface: v2.00
usbcore: registered new interface driver uvcvideo
USB Video Class driver (v0.1.0)
i2c /dev entries driver
Driver 'sd' needs updating - please use bus_type methods
omap2-nand driver initializing
NAND device: Manufacturer ID: 0x2c, Chip ID: 0xba (Micron NAND 256MiB
1,8V 16-bit)
Creating 5 MTD partitions on "omap2-nand.0":
0x000000000000-0x000000080000 : "X-Loader"
0x000000080000-0x000000260000 : "U-Boot"
0x000000260000-0x000000280000 : "U-Boot Env"
0x000000280000-0x000000680000 : "Kernel"
0x000000680000-0x000010000000 : "File System"
UBI: attaching mtd4 to ubi0
UBI: physical eraseblock size: 131072 bytes (128 KiB)
UBI: logical eraseblock size: 129024 bytes
UBI: smallest flash I/O unit: 2048
UBI: sub-page size: 512
UBI: VID header offset: 512 (aligned 512)
UBI: data offset: 2048
UBI: attached mtd4 to ubi0
UBI: MTD device name: "File System"
UBI: MTD device size: 249 MiB
UBI: number of good PEBs: 1990
UBI: number of bad PEBs: 6
UBI: max. allowed volumes: 128
UBI: wear-leveling threshold: 4096
UBI: number of internal volumes: 1
UBI: number of user volumes: 1
UBI: available PEBs: 0
UBI: total number of reserved PEBs: 1990
UBI: number of PEBs reserved for bad PEB handling: 19
UBI: max/mean erase counter: 24/1
usbmon: debugfs is not available
ehci_hcd: USB 2.0 'Enhanced' Host Controller (EHCI) Driver
ehci-omap ehci-omap.0: OMAP-EHCI Host Controller
UBI: background thread "ubi_bgt0d" started, PID 407
ehci-omap ehci-omap.0: new USB bus registered, assigned bus number 1
ehci-omap ehci-omap.0: irq 77, io mem 0x48064800
ehci-omap ehci-omap.0: USB 2.0 started, EHCI 1.00
usb usb1: configuration #1 chosen from 1 choice
hub 1-0:1.0: USB hub found
hub 1-0:1.0: 3 ports detected
Initializing USB Mass Storage driver...
usbcore: registered new interface driver usb-storage
USB Mass Storage support registered.
g_ether gadget: using random self ethernet address
g_ether gadget: using random host ethernet address
usb0: MAC 72:35:4d:d3:da:76
usb0: HOST MAC 7e:6d:20:01:83:47
g_ether gadget: Ethernet Gadget, version: Memorial Day 2008
g_ether gadget: g_ether ready
input: omap_twl4030keypad as /class/input/input0
ads7846 spi2.0: touchscreen, irq 187
input: ADS784x Touchscreen as /class/input/input1
twl4030_rtc twl4030_rtc: rtc core: registered twl4030_rtc as rtc0
OMAP Watchdog Timer Rev 0x31: initial timeout 60 sec
cpuidle: using governor ladder
cpuidle: using governor menu
register sdio_ti_driver is OK!
Registered led device: led0
Registered led device: led1
Registered led device: led2
Registered led device: led3
usbcore: registered new interface driver usbhid
usbhid: v2.6:USB HID core driver
Advanced Linux Sound Architecture Driver Version 1.0.19.
No device for DAI twl4030
No device for DAI twl4030 Voice
No device for DAI omap-mcbsp-dai-0
No device for DAI omap-mcbsp-dai-1
No device for DAI omap-mcbsp-dai-2
No device for DAI omap-mcbsp-dai-3
No device for DAI omap-mcbsp-dai-4
TWL4030 Audio Codec init
asoc: twl4030 <-> omap-mcbsp-dai-0 mapping ok
ALSA device list:
  #0: omap3evm (twl4030)
TCP cubic registered
NET: Registered protocol family 17
NET: Registered protocol family 15
RPC: Registered udp transport module.
RPC: Registered tcp transport module.
Power Management for TI OMAP3.
SmartReflex driver initialized
VFP support v0.3: implementor 41 architecture 3 part 30 variant c rev
omapfb: using mode 7inch_LCD
Console: switching to colour frame buffer device 100x30
GPIO-153 autorequested
omap-dss DISPC error: Requested pixel clock not possible with the
current OMAP2_DSS_MIN_FCK_PER_PCK setting. Turning the constraint off.
Display already enabled
Display already enabled
Buffer Size = 3686400
omap_vout: registered and initialized video device 0
Buffer Size = 3686400
omap_vout: registered and initialized video device 1
twl4030_rtc twl4030_rtc: setting system clock to 2011-10-03 12:27:06
UTC (1317644826)
UBIFS: mounted UBI device 0, volume 0, name "sbc8100-rootfs"
UBIFS: file system size: 252112896 bytes (246204 KiB, 240 MiB, 1954
UBIFS: journal size: 9033728 bytes (8822 KiB, 8 MiB, 71 LEBs)
UBIFS: media format: 4 (latest is 4)
UBIFS: default compressor: lzo
UBIFS: reserved for root: 0 bytes (0 KiB)
VFS: Mounted root (ubifs filesystem) on device 252:1.
Freeing init memory: 164K
Kernel panic - not syncing: Attempted to kill init!