have unstable working condition with DVI and USB host

I have just experiemented unstable working condition with DVI and USB host. I use the image built by bitbake console-image.
At the beginning they were working fine. I can boot to the Angstrom Screen on DVI and I can use KeyBoard through the USB Hub. But after restarting for 5 or 6 times, I cannot use the Keyboard anymore. On LCD I can only the boot screen at the u_boot stage but I cannot see the Angstrom login screen. What I only have is the Terminial login on Minicom.
Could you please tell me what happen?

Best regards,
Thang Nguyen

So, you know the kernel is running fine because you have a login screen and can interact fine via the serial port, but both the USB and DVI-D have stopped? The DVI-D still displays the Beagle logo?

I noticed that I get that problem if I have certain usb devices
plugged into the hub - mostly usb wifi adapters. Unplugging that
usually fixes the problem. Boot up and plug back in.

- Dan

no, it’s just there is no signal. I don’t understand why?

this doesn’t happen with the image I got from Angstrom. But I think my USB Hub has problem.