Why does '97 Mustang GT, 5spd man.trans, go into 5th when I release his clutch?

What is your question?

Shifts into neutral fine and even feels as if he's properly in gear I move to, but once I let off the clutch.....he's always in/ends up in 5th gear. It doesn't matter if I go to 1st, 2nd, 3rd or 4th from neutral position. I'm always in 5th once I remove my foot from the clutch. Can any one possibly pin-point the problem or guide me in right direction of whether he needs new trans altogether or can I remain hopeful of fairly simple repair/rebuild? Any and All suggestions or advice given is Greatly Appreciated.