I am running my midifiles on a Compaq Presario 1200, laptop, using Cakewalk 9.0, a USB connection into a midiman 1X1, to a Yamaha Portasound 225, then using the headphone connection out to my powered mixer. This once worked fine. The midis don't sound bad but, I'm noticing that during segments of each song, the song hesitates (seems to temporarily slow down)periodically, and I can't figure out why. This definately won't work during live performance, and I don't know what to do about it. I've run diagnostics on the computer, hard-drive, etc. and that all seems o.k. Anyone got any ideas of what the problem might be?