u-boot splash is corrupted and disappears

I have tested u-boot splash using either orange solid colour or a
generated beagleboard image. The orange colour disappears before
angstrom splash
pops up. The beagleboard splash is first corrupted, then disappear.
This happens when kernel starts to run. I have disabled virtual
console. But it doesn't help. some guy must write something to and
clear video framebuffer in kernel initialization. Although I set same
resolution (1024x768) at u-boot env. as in u-boot, I notice screen
resolution is always changed to 1366x768 once the kernel starts. I am
not sure if it has something to do with this issue. Someone has
reported this issue before. I just wonder if this issue has been

I believe this is about where the kernel is loaded in memory.