That is very strange. What if you just delete the config.cfg file? And check the file system for errors?
I deleted config.cfg and the problem still persists.
I ran a chkdsk on H:\ (my sansa clip zip):
Windows is verifying files and folders...
File and folder verification is complete.
Windows has checked the file system and found no problems.
3,926,044,672 bytes total disk space.
8,192 bytes in 2 hidden files.
208,896 bytes in 50 folders.
347,385,856 bytes in 414 files.
3,578,437,632 bytes available on disk.
4,096 bytes in each allocation unit.
958,507 total allocation units on disk.
873,642 allocation units available on disk.