I tend to use MainStage as you would a hardware module. My Motif ES8 provides sequencing info and I use a number of software instruments (anywhere from 2-5 - some MS some 3rd party) during the course of a song to provide additional instruments. FYI I use a Macbook pro intel core 2 duo with 4gb ram and a 7200 rpm HD. The cpu meter always reads low but even when there is a minimum number of instruments playing (sometimes just one) MainStage will spike. Not always but at times there will be dropouts when it does. The frustrating thing is that it's somewhat random. Today for example, I rehearsed our 3 song set and everything was fine. When we played, during the last song, I could hear a dropout at the very end. I noticed also that when the computer was just idling after the service with MS up, it would randomly spike even though nothing was being played.
Research has shown that other people have experienced this and I've tried all of the recommended fixes (turn off airport; uninstall/reinstall; etc.). I was wondering if anyone else has experienced this or has anything that might be worth trying to solve the problem. Thanks.