So after doing a transmission rebuild and getting the computer reprogrammed, everything seems to be working great...EXCEPT...

When I start the car after sitting overnight or for a few hours and shift into reverse it seems like it does not want to reverse. If I give it some gas it does go but it seems like it takes more effort. However, if I go back into park while its still running and then go back into reverse, it works perfect. I took it back to the shop I had it rebuilt at, and they said it was nothing to worry about...but I just want to double check with you guys.