But it isn't too much trouble to pass a copy of the array instead of the original.

I'd be happy to test a copy of a binary which tried this functionality.

Another thing to consider... I'm probably running a different model of GPS than you are, and I can't reproduce the bug when there's no serial communication going on, so perhaps there's something about the serial communications that are going wonky and causing this?

Here's another couple of things that makes me think of serial:

- Sometimes, when I start GPSapp, the music hiccups as GPSapp starts up.

- Sometimes, GPSapp displays a blank black screen for a long time (even as long as 20 seconds on occasion) before the first "Waiting for data from GPS receiver" message appears.

The "Waiting for data" message never does more than a brief blink, so once the receiver is connected then the communication happens fine. But there's that long black pause before the first message is even listened for that makes me worry that the app is having trouble talking to the GPS on the serial port at first. Any idea whether that might be related?