iMac doesn't recognize thumb drive
I have a thumb drive that I previously used (prior to Lion upgrade) to move files from a pc to my iMac. Now my iMac no longer recognizes my thumb drive. Help... need an easy way to move common files (video/spreadsheets/etc.) back and forth, some are too large for email or burning to a cd.
iMac, Mac OS X (10.7.2)