We loaded QNX 6.4.1 on three Transcend TS16GSSD25-S solid state drives.  The motherboard is Advanced Digital Logic's 
MSM855 P738 1.4 GHz PC104, etc.

The OS runs for awhile, then hangs.  Photon does not respond, the ethernet connection from a laptop to an expansion card
 hangs, and there is no further response from the OS.

Except for the use of a hard disk (HItachi HTS548080M9AT00 80 GB) instead of the solid state drive, we have used exactly
 the same hardware and software for months (at least a year, closer to two years) with no problem.

Does anyone have any advice, such as whether to use a particular driver, or some configuration change?

Thanks very much!