Automatic Shifting Problems HELP!!!!

[RawnC]

Ive got the 3100 v6 with automatic transmission. This all happened AT ONCE!
1) The button on the shift knob got locked up, cant press button in.
2) The shift knob now moves without the button being pressed in.
3) The shift knob now moves (even out of park!!) without key in ignition.
4) Putting in Drive tries to do everything in 3rd gear.
5) Have to manually shift to 1st, 2nd, to avoid accelerating from zero in 3rd.

This all happened as soon as my new rims were put on, but that wouldnt have anything to do with this would it? The 1st actually feels more like 2nd but I cant be too sure. Just in case I want to fix this asap. Please help!

[maxwedge]

Get the shifter and linkage checked out.

[RawnC]

Where is the linkage located?

[maxwedge]

It goes from the shifter to the trans, cable operated. If you are unfamiliar with this area, get a pro to help you out here.