Thank you for all these precisions, it sure does help me a lot!
The Memory Stick corruption issue appears much clearer to me now. Indeed, a MS should never been taken off in case of a crash as Palm OS cannot manage correctly the closing of the VFS (Virtual File Manager) when it is itself not in good shape! This should be a correct explanation.
I know one case when iziBasic could crash when being launched (this is already fixed in the next release being developed): the MemoDB must be initialized, meaning that before using iziBasic the Memo Pad application should be opened at least one time, even if not adding any memo to it.
If this is the case (especially after a hard reset), open the Memo Pad and exit immediately from it before launching iziBasic for the first time.
That could potentially fix your main issue.
The Backup MS-Backup could indeed be very useful, furthermore it would avoid you to do all of the testing (and I usually do not like to harass my gentle users with this kind of tests!), but this would require me to find the emulator for your exact Clié NZ90 device. This will not be a so easy task to perform anymore since Sony closed all their Palm online resources
If you send me this backup, I of course promess not to look into your personal data and to remove all files from my computer as soon as I will not need them anymore.
Cheers,
aldweb