tranny slipping

[leanburn]

i got my car out of storage a couple weeks ago and installed a gear vendor unit. when i went for my first run the tranny slipped really bad a couple times when i tried with the hammer down. i finally activated my trans brake for ****s and giggles and everything was fine for some reason. oh yes this is a reverse manual by the way.
 i have ran the car about 100 miles on the highway and 20 miles in town and on two occasions it slipped in first gear when slowly taking of from a standstill, i emiediately went to neutral then back to first and thing where good again. i have also noticed a very minor ''clunk'' when slowly taking off at about 5mph, but not when i mash it. it does not clunk if i brake torque it, it only happens when i actually move.
 anyone with any ideas?

[tactransman]

Have you checked the fluid level in neutral?

[leanburn]

yes always in neutral. i had a tranny guy look at it, he said all the bands are fine [ he tested them ] everything looked good except the valve body had a sticky valve    he cleaned it up and thought that was the problem but it wasn't so he adjusted my cable going to my shifter and it seems better. how finiky is the adjustment on these manual bodies?

 another question, is there anyway that a gear vendor can slip? everything was fine until we added the gv unit.