SanDisk Cruzer Enterprise USB flash drives use a fixed 256-bit key for obtaining access to the cleartext drive contents, which makes it easier for physically proximate attackers to read or modify data by determining and providing this key.
http://www.vupen.com/english/advisories/2010/0078
http://www.syss.de/index.php?id=108&tx_ttnews%5Btt_news%5D=528&cHash=8d16fa63d9