Same 6sp problems, different day

I have an 09 6sp. At 4500 the tranny was replaced cause it got stuck in 4th gear and they said it burned out a bunch of bushings and synchros. At 30k, immediately after a toyota service, the tranny was grinding between 2nd and 3rd. The transmission was removed, a couple bushings from the shifter plate were removed as they said the original replacement included a couple of extra bushings that made the shifter plate not sit correctly (I knew it wasn't going to help but whatever). Tranny was reinstalled, same problem, tranny was removed and completely rebuilt as the 3rd gear synchro bushing was completely worn out. At 34500 the clutch explodes and the tranny is removed yet again and the clutch is replaced per that good old TSB. Now at 59000, I changed all fluids to Redline 75w90 (trans, transfer, diffs), a couple hundred miles later between 3rd and 4th, starting at around 4000rpm, the grinding between gears is back.
I'm having Toyota take a look at it and see if the transmission needs to be rebuilt, again. But any ideas on what could be causing this? Too much slip with the clutch, not the correct fluid, etc? Any help would be helpful. Thanks guys!

 

yeah yeah, I actually thought about that this morning on the way to work, ha!

 

swap in a racing sequential