If you are having problems with USB-based flash drives after upgrading to Linux Kernel 3.2, then you are not alone. My workstation would ended up kernel panic when i insterted my flash drive, works with it, and then unmount it.
There's a new stable kernel released by Greg which happened to have a lot of usb fixes. Hopefully this update works like charm to fix my problem (and yours). Strange thing is that it didn't happen on my desktop. All flash drives are working just fine.