Linux wont boot after Apex is replaced

[Steinar Midtskogen <steinar@latinitas.org>]

Thanks to Martin Michlmayr who solved my recent root mount problem.  I
have one more problem.  My NSLU2 has 64 MB (replaced memory chips, not
stacked), so I replaced Apex using the instructions at
http://www.nslu2-linux.org/wiki/Debian/FatSlug in order to get Apex to
detect it all: I used slugimage to replace Apex with
http://ipkg.nslu2-linux.org/feeds/kernel/apex-debian-nslu2-arm-1.5.14.bin

The new Apex detects 64 MB now, but it's unable to boot Linux.  It
loads the kernel, prints "done, booting the kernel" then halts.  The
memory is good, I've run OpenSlug with 64 MB previously.

I reinstalled and downloaded the mtdblock2 image posted by Marc Singer:
http://www.mail-archive.com/debian-arm@lists.debian.org/msg09293.html

I cat'ed it to /dev/mtdblock2 and rebooted.  Again the new Apex
detected all the memory, but Linux still wont boot, it halts after
"done, booting the kernel".

Any ideas?

And, how can I go back to my old Apex which boots Linux (with 32 MB)
without reinstalling Debian?  If I reflash the official image, it
boots the installer.  I also copied /dev/mtdblock2 after installation
and reflashed using that, but it still loads the installer.

-- 
Steinar Midtskogen