First I compiled the kernel (from
kernel.org) with only the default settings, except for enabling dm-crypt, and without any patches. This worked well, but I guess it's probably better to use the more extended configuration and apply the patches.
That's why later I used cbxbiker61's 2.6.30.5
kernel configuration you mentioned. I also enabled the crypto loop device and crypto hardware drivers (though I have no idea if that driver is suited for the sheevaplug). In addition I applied those patches that worked without problems (some don't seem to be necessary anymore).
I uploaded the binaries to my sheeva plug

, so if you want to try it, just download it here:
README-2.6.31-rc6. It should work like cbxbiker61's scripts.
cbxbiker61, could you maybe host this, so there's a single location for the prebuilt kernels? Or maybe you could also support the 2.6.31 release candidates? That would be awesome.