Jumping NEedles

Hi all. I have a 96 cherokee Sport. When accelerating, the speedometer needle will sporadically(sp?) jump from 5-30mph. Once I hit 30-35mph, everything's fine. When the speedometer is jumping, the tach also jumps. Please help. I have no clue!

I have the same a 96 cherokee sport. However, my needles are only jumping when they are working, the rest of the time they dont move. The only ones that dont work are the speedo, tach, and gas guage. Sometimes if im in reverse they will work, then other times they randomly work but are jumping like yours. If anyone has any solutions please let us know.