I had this exact problem. It would 'stick' and stay between 5/6 and under reverse before SLOWLY returning to home position between 3/4. It stuck bad enough that I ended up re-selecting reverse instead of engaging 1st because the stick wasn't coming off the lock out fast enough. I'm also lucky that I never managed to re-engage first instead of 3rd when shifting.....
The dealer had initially checked to see if the shifter pivot ball was greased (it was) and decided to try replacing the entire shifter assembly. When they removed the assembly, they saw the rod linkage was rusted. Replaced that and it's free moving again.
Dealer (and I) speculate that the boot that covers the ball joint kept on collecting water during winter/car washes and eventually washed out all the grease inside the boot. Dealer replaced parts and loaded the boot with grease...
I forgot to ask for the original part to visually confirm that it was rust/debris causing the issue at the joint.
Mine was repaired under warranty.
http://www.ft86club.com/forums/showt...hlight=shifter