Hi,
| have very similar problem, but not exactly. It's about 2 weeks since I second-hand Zaurus SL5500 (I wanted this cool device since SL5000 were released so I was very happy to buy it here because it never had been sold here officially).
But when I connected to internet over wifi, I tried to install some new applications (in Zaurus was some old OpenZaurus - may be 3.1 but I'm not sure). Only one feed which I found on openzaurus.org was for 3.5.1, so I try to install firefox and some other apps from this feed. Yes I know. First mistake. Second was to stop installing before it was finished (nothing has happened for about 20 minutes).
After that no application can be run and after soft reset I doesn't boot. It doesn't boot even after hard reset Only Openzaurus logo is figured and white cursor blinking, but kernel doesn't begin boot.
OK, I wanted to flash anyhow so I purchased new CF card (F1 40x - 1G) and USB reader/writer. I downloaded openzaurus 3.5.1 and ... nothing. I do all according to howtos I found here on zaurususergroup and on Sharp itself (CF is FAT16 formated, I pluged Zaurus to AC adapter, I renamed files to initrd.bin and zImage, battery switch).
While I holding C and D button and push FULL RESET both leds begin blinking. I've also try other kernels and also I'have tried original Sharp Ospack and nothing. Only blinking leds. Does anybody have idea whats the problem?