Two times now I have noticed that my USB stick cant be accessed. It has happened in Vista 32bit and now in Vista 64bit. I have roboform2go and truecrypt (portable versions) on this stick. I can see the drive letter for the stick but it can not be accessed. I have to format the stick to access it and store files. Tonight there were some kind of update (windows update) maybe that is the culprit? Anyone have any idea why this happens? Maybe happened to you? Is it just a faulty USB stick or can there be other reasons?