B3120: Windows sometimes recognize USB storage as blank USB storage

I use Parallels with manual USB connected (because sometimes other USB devices is in-use on Mac). When I manually connect the USB storage, I get that USB storage with a blank (means nothing on it) but when I disconnect it and reconnect to Mac (or other machine), all data still exist.

On automatic connected situation, sometimes I get Kernel Panics, otherwise; everything works fine.

PS. My USB storage is just a small flashdrive. (1GB)

 

This happens to me also in build 3120, but only in Windows Vista (Regular VM). My flash drive works fine in XP Pro (Boot Camp) in Parallels.