Click wheel problems with Aux Pod/Ipod2Car

[slayer6x6]

When I try and scroll with the click wheel when my ipod is pluged into my car, the click wheel doesn't work. The actual buttons work, but when I try to scroll the cursor doesnt really move it just kind of jumps around. I have tried two different ipod interface products, and a buddy of mine has the same problem with his. Just wondering if anybody has this problem or if there is a fix. I basically have to unplug the ipod if I need to do any scrolling.