I have a big patch that ultimately outputs to an arduino that then controls relays that fire strikers that play a gamelanish assembly of music. Here's a link to vid of the working machine:

So the problem is, it works great, always seamless on my computer (MacBook Pro (15-inch, Early 2011) 2 GHz Intel Core i7 4 GB 1333 MHz DDR3, but when I try to run the exact same patch to the same arduino using another machine (last attempt was a MBPro 13 inch mid 2010, 2.4 ghz intel core 2 duo 16 gb 1067 mhz ddr, but it's happened before on a machine I don't have the specs for right now) the comport almost immediately runs into serial overruns and shuts down the comport. I'm running at 115200 baud.

I'll admit I'm not using the most efficient means of serial communication, but aside from that, it does work on the machine it was written on. The machine that it is not working on is more powerful than the one that it is...do I have a magic computer?