Yes, this is a known user experience flaw. Program is busy doing something and the whole app locks up. It appears as though its stopped working as it doesn't respond to user input, and windows thinks it is dead when in fact it's locked up doing whatever process and will eventually come back to life (most of the time). It's on my list to suggest as an improvement - add some sort of 'Busy processing' or progress bar to let you know it's busy.

I've had customers send in tickets with them clicking on publish, then clicking within, getting the Xara has stopped responding message and clicking close lol.