manual transmission slips when hot

I have a 1994 saturn SC2 with 108k miles and about 50k miles on a new clutch. My problem is after the car gets hot the transmission will slip in low RPM's if I give it too much gas. Once I hit about 3k RPMs it will stop slipping and grips just fine. I'm not sure if this is just because my clutch doesn't grip well and the torque produced on it at these lower RPM's is causing it to slip or what. Please let me know if it's time to get a new clutch or if it may be something else. I should also say this problem is worse when the AC is running.

There is nothing in a manual transmission that will allow 'slipping'. It must be a bad clutch.

Although it does sound like a clutch plate/pressure plate problem, another thing to check would what Saturn calls the Clutch Hydraulic Release cylinder. I call it the slave cylinder. It could be sticking, not releasing fully. The clutch master cylinder wold be in front of the brake pedal somewhere, and it too could be sticking, not working smoothly.