My USB stick will not re-mount. An alert is popping up telling me to re-attach the stick, but this doesn't help.
This can happen when the USB stick is not cleanly unmounted from the Windows PC. If you simply unplug the USB stick from PC without using the little tray icon to detach the hardware correctly, the volume will be marked as "not cleanly unmounted". There might be some dirty sectors left and Mac OS X will not be able to re-mount in read-write mode for that reason.