Okay, this is weird. It is definitely the same exact binary, segfaulting on the r&d-virgin N900 at bootup, but not on the development one where it no longer does.

So there is still more work do be done, I am missing something somewhere. But for now, I am out. Sleep. Needs to happen. Besides that, I updated the source once again in case the above post didn't make that obvious. I cleaned up the code that handles the R&D-virgin N900s correctly (there was a cal_finish() call left in one of those code paths from years ago, and I fixed the messages it provided to be more meaningful thanks to me getting new understanding of what they mean myself, and made it actually properly distinguish between the 'R&D virgin' error and the other errors that might be returned - I also made it use the cal.h defined macros for the return values of cal_read_block instead of just going by the numerical value as the old code did..

Edit: P.S. reinob, etc, anyone still left with an N900 that hasn't been R&D mode turned-on, ever?