Can't Pull Bar to Mount Storage
When you're done transferring these files, it is more important that you eject the device from the computer than it is for you to unmount the SD from the statusbar. 

Once your computer says the device is ejected, the problem should be resolved after you unplug the phone-- 

If not-- you can transfer files via adb without 'mounting' the sdcard. 
In this case, you would not disable the debugging option (Which you don't really need to do in the first place, btw).

=D