WinCE was an interesting beast. The ones we made were MIPS (picked over an ARM system). Running a wildly patched 2.12. Also your PCMCIA issues? Trust nothing. It could be anything. But my guess is it is the driver, as getting that type of flash card to work consistently and correctly takes a steady hand. Your flash could also be slightly corrupt. We had almost that exact same chipset and found it would randomly stop taking commands after awhile and the flash leveling would cause writes to time out leaving half written pages. You also discovered Visual C++ for wince has a lot of interesting bugs. I think it got so bad we were about to start breaking each method into one cpp file as things could 'smear' between methods before the whole thing went EoL. There are newer versions of the compiler that may help some (maybe you already have it). If you got into the right program (or the right company) you could get the ODM build set. Which would compile the whole OS (based on a very bespoke version of visual studio 6 and a crazy mixture of using mklink and crazy batch files). But it would also let you debug the drivers. As for my 'trust nothing' I mean it. The API calls that should 'just work' may randomly crash or leak. Good luck!