rpm and mph gauge in synch?
 

i recently noticed that my cars odometer gauge faded out..... and that sucks, but then i was sitting at a light with a friend and i was reving my engine a little nd i noticed that my mph gauge was moving with my rpm gauge.....but i was sitting still.....i was wierd and im not tii sure how long its been doing this. i hardly ever look at that gauge when im at a light. anyway if anyone might know about a fix to this problem i would appreciate it.
loren