Sorry I'm late replying here but check out these other threads for more tips and ideas. Also check to see if your shifter cable sheath has separated.  I had mine do this and I described it in these posts.

http://talk.newagtalk.com/forums/thread-view.asp?tid=261204

http://talk.newagtalk.com/forums/thread-view.asp?tid=199252

http://talk.newagtalk.com/forums/thread-view.asp?tid=147498