I've been trying to do something similar.
What I've learnt are these:
- u-boot and uImage kernel should match (both were compiled for the same target, e.g. beagleboard, or devkit8000, has something to do with board id I think).
- both devkit8000 uImage kernel and beagleboard uImage kernel can be used to run angstrom in devkit8000, but both has their plus and minuses. The beagleboard kernel wouldn't detect ethernet, whereas the devkit8000 kernel would. I am using 2.6.35 kernel for devkit8000 which I compiled from the GIT repository at gitorious.org/devkit8000.
- framebuffer is still an issue (i want to display to TV)
These are my boot options: (nothing special)
setenv bootargs 'console=ttyS2,115200n8 root=/dev/mmcblk0p2 rw rootwait video=omapfb:mode:720p60'
setenv bootcmd 'mmcinit;fatload mmc 0 80300000 uImage;bootm 80300000'
Try using all MLO, u-boot.bin, uImage and rootfs from the angstrom demo page **broken link removed**
I think it worked for me in the past (despite all its problems like no internet in devkit8000 etc.)