I have the same problem as DeathLog. (well, the earlier problem, before brickage...)
I got my C860 yesterday. Got my 256mb CF today. Did a NAND backup to the CF, the tried flashing.
The 02-24 pdaX release: regardless of partitioning, everything appears to succeed (although differing from instructions) but when restarted (with or without full powerdown in the middle) all I get is the Tux logo from the kernel, and it goes no further.
The 02-17 pdaXtest release: Everything appears to succeed, but when restarted this one too just shows me a cute little penguin and nothing more, ever.
I can restore my NAND backup and it works fine, and I\'ve done so between several (but not all) reflash attempts. I\'ll keep trying and post any interesting results here.
j