Timing off when triggering clips... anyone else?

[edIT]

I am running Live 5.02 on a 1.67 G4 laptop 1.2 gigs of RAM. My live set is set up in a way that I have 2 columns loaded with full songs and then one column loaded with aprox. 20 loops (8 of which) can be triggered via a trigger finger. I have about 4 more columns also loaded with loops that are like storage bins, and I move the clips over to the "loop trigger" column when i want ot use them. Recently about 20 minutes into my set, the timing will be a little off. I'll hit the trigger finger and the loops will trigger aprox. and 8th note later. I am using 16th note clip trigger quantization, and it's normally perfectly on beat at the top of the set, but then it becomes late and I pretty much can't perform from that point on. Is anyone else expereincing this?