New Trans, lost reverse...

Hey guys! My brain is fried for the day and I'm sick of looking at the car so I thought I'd ask on here. Brand new PA Performance 904 trans and converter kit http://www.summitracing.com/parts/pma-pa12104/overview/make/plymouth . All I've done as far as driving the car has been in and out of the shop, and reverse has worked great. All of the sudden, the car lost reverse. With the car in reverse, reverse kind of comes and goes. It will go in reverse a couple of seconds and then do nothing, then work again for a couple seconds more at random intervals. Ive tried unhooking all of the trans linkage and shifting it by the shift arm on the trans and same deal, reverse comes and goes. Fluid is correct, and all forward gears, park, and neutral are ok. Any ideas? This has drove me whacky today. :banghead: ](*,):dontknow::cussing: Thanks in advance for the help! :prayer: