Whenever I try to use the underlay tool (either through the file menu or from the underlay toolbar - underlay image properties button), PCStitch stops working. All it will do is make that error beeping noise. From previous experience, when the underlay tool was working, it pulled up a box for input, and I suspect that the fact it's not showing is the problem. I have to force close PCStitch whenever I try this. Any ideas what the problem could be? I have two monitors, if that makes a difference.
I suggest you try uninstalling and then re-installing PCStitch. It should not affect your license. If that does not help, then contact Mark and explain in as much detail as you can what is happening.