I would try reformatting the flash drive. Assuming you are using XP/Vista, take all the files and back them up on your computer, then you should be able to right click it in "My Computer" and select format. It will wipe everything already on it, but should clear any sort of restriction. Stick all your files back on it and you should be fine.

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TC
Current stable:
- 2004 Mazda RALLYWANKEL
- 2007 Saturn sky redline
- 2004 Explorer...under surgery.

Past: 135i, GTI, 300E, 300SD, 300SD, Stealth