Yes, I know for certain now that that's the case, as it works as it should (even the showMessage...) if I use the main thread to do the reading and parsing. I don't know if there is any drawback to doing it that way, but there shouldn't be since I don't use the GUI in these cases anyway (when the program essentially is a component to Arena).

Actually there is one drawback, and that's that I can't receive anything while my program 'thinks' (makes up a move, which could take time). I don't know how important it is to be able to receive in these cases. Of course the official recommendation is to always have it reading, but I'm not running av power plant and I don't think it's a big deal.

On the other hand, now that I know that some areas are "off limits" to the second thread, including GUI handling, I might be able to get that thread working.

Anyway, thanks for the help.