ive done that a few time when resieing the quick launch bar.
what it is, is one or your tool bars has kinda wraped it self around, i know that sounds weird..
You need to either turn off the offending tool bar or pull it back to ware it should be, it may not be a case of Left or right but rather up and down
try pulling the move handles up and down, i just gone and messed up my tool bars. dang