OK, not sure if this will address anyone's problem here, but IIRC someone earlier mentioned using a 256M CF (macroexp?). Anyway, I'm trying to use a Viking 256M CF, and having all kinds of trouble. I used to have a 128M CF that I lent out, and I used to flash like mad w/ it. Then I "upgraded" to the 256M, but wasn't flashing (had my Z dialed in). But I digress - I think the 256M CF is giving me grief - I just didn't make the connection because I'd had the 256M for a long time before I tried to flash w/ it.
After trying to flash a recently purchased SL-5000d, and pretty much bricking it, I started nosing around to figure out what the problem was. First thing I checked were the files that I downloaded from openzaurus.org. I noticed that when downloading the files via Safari (Mac user), the download would complete "successfully", but would be the wrong size and MD5sum. So, I really started getting picky about my MD5s (wget worked so much better than a browser, BTW), checking them all the time.
I found that copying my files from the Desktop to the CF via the GUI (i.e. drag and drop) would hose the files - bad checksums on the files copied to the CF. Copying them via "cp" in Terminal - same thing. I ended up tarring everything up, and copying the tarfile - that seemed to work (using "cp" in terminal - why that worked and the individual ROM files didn't still confuses me): The MD5sum of the tarball was the same on my HD as the CF. Untarring everything and the files had the right MD5sums - hurrah. I flash the unit, certain that my woes are behind me, but it still won't boot. Completes the flash process in just under 3 minutes, but still no dice. WTF?
Then I check the MD5sums of the files on the CF - bad. Again, WTF? Just flashing and both initrd.bin and zImage are wrong. #$^%, even the tarball I moved over there previously was bad. I copy files over to the CF, and they are good - flash the unit and they aren't.
Unlike SD, I don't know how to make CF read-only - if that would even work anyway for flashing. But tomorrow, I'm going to buy a 128M CF, and see what happens...