This has only been reported by Mac users. We think there is an OSX version problem/incompatibility with the binaries we're building. We avoid this problem in Linux by not distributing PixyMon in binary form.
If PixyMon is crashing, we'd like you to send us a note (support@pixycam.com) so we know which OSX versions need more testing/work, and we'd also like you to try to build PixyMon on your machine. It's easy, and it's likely to fix the crashing problem. And if it doesn't, let us know!