shifting problem

I have a serious problem with my 87 jetta. Its stuck in third gear. Cant seem to dissengage it. Clutch seems to work ok. Not sure if the problems in the tranny or linkage. Please help
Can't anyone help me with a little advice as to were i should start. No one has had this problem? I am dying here. Any suggestions would be most appreciated.

check out Jetta stuck in third gear thread top of this page
might help