FWIW I have a 16GB Cruzer, with U3 on it even, and when a 6GB backup file failed to be written to it due to the FAT32 limitation I backed up the files on it, reformated it to NTFS, restored my files and have been using it fine every since.
I understand your problem but I don’t understand the cause of it. It could be caused by a broken wire in the Cruzer, a static charge zap to it, a spike in the voltage to it from a USB connection, a low voltage power supply, a software security app, etc. But not your conclusion.
Have you called SanDisk support and asked them?
