Reply to Traktor Pro 2 load meters spikes all of a sudden?

After using TP2 pretty much since it came out, I was using it at a gig last evening , with the same latency settings I've always been using it with, and all of a sudden the load meter was going through the roof (in the reds), with massive distortion, and audio drop outs, stalls, etc.

Keep in mind I had both decks playing and I was using the custom DJTT S2 mapping jog wheel effects on one side but I've done this so many times before and never had an issue. Even after I stopped it playing one side, the load meter was still in the reds. Even after I changed the latency settings to be 18+ms (compared to 12.1 previously), it was no problem. I don't do a lot of cue point juggling and never scratch, so having the latency at 18 is ok, but I'm really curious to know why this became a problem all of a sudden.

It does seem like my computer runs hotter than before, however I can still hear the fan going. Could that be an issue? This literally just happened yesterday, while I was at a gig. However the evening before I used it at a gig and it was just fine. One key difference is that on Friday when it was running fine, I had the S2 running through a separate line level mixer so the volume was a lot lower. Yesterday I had the speakers plugged directly into the S2. Could and had the run the master much higher. Could that also be an issue?