Yes, upgrading U-boot to the version here (http://www.plugcomputer.org/index.php/us/resources/downloads?func=select&id=15) or upgrading to a custom compiled version from the latest git repository will fix the problem.  The factory U-Boot and kernel apparently use the incorrect  architecture number.

Now if only I could access the sd card from u-boot.

Yeah, you definitely want to apply the Marvell patch set to the vanilla kernel.  It patched pretty easily against 2.6.34 using the directions in the wiki.

I loaded my kernel from a USB stick.

Also, I have the April version of uboot running on mine.

I was finally able to get 2.6.34 to boot by upgrading the uboot to the latest version on this site.  Once you upgrade though, you'll also have to flash the kernel to the latest version on the site since the factory default one stops working after upgrading the uboot.  You may also want to upgrade the root file system as well to make everything happy.  Once I did all that, my custom 2.6.34 kernel finally booted.

The reboot issue that everyone is mentioning seems to be related to the wireless.  I consistently have reboot problems when the wireless drivers enabled with the wireless chipset firmware loaded and running.  I would be willing to bet it's something related to the drivers or the firmware.

Thanks for the tips. 

I figured out the problem.  It seems as though the factory configuration of these devices doesn't work that well.  As soon as I upgraded the uboot to the latest version on this site, I was able to boot my custom kernel, but not the factory one.  After that, I reflashed the kernel and root file system and everything seems to be happy.  Now I can proceed with my own kernel and installing debian squeeze on it.

As far as I know, the settings I have should work.  They are the same as the factory settings with the exception of where the kernel is loaded from.  What did you do differently?  Would you mind posting your uboot settings?

Yes,  I did compile in console access.  It definitely boots on my SheevaPlug (at least until it tries to mount the root fs, but that's what I expected), but not my GuruPlug.

In U-Boot it is configured the same as the default boot with the exception of the kernel loaded from usb.  I basically changed the environment variable for the kernel as shown below to load the kernel from a usb stick instead of from the nand flash.

setenv x_bootcmd_kernel fatload usb 1:1 0x6400000 /uimage

I'm trying to run a custom compiled 2.6.33.4 kernel on my guruplug.  It's using the default guruplug kernel configuration and was compiled with the latest code sorcery compiler (2010q1-202).  I'm trying to load it from a usb stick.  After loading the kernel it hangs on  boot following the "Uncompressing Linux... done, booting the kernel."

Any clues why it would hang?  The same kernel will boot on my standard SheevaPlug.