I created a Module on ModPlug then I minimized ModPlug to type up some lyrics to go with what I created, after I did so I pressed the play button and ModPlug crashed. after restoring the module from an autosave I was able to play it just fine, until I minimized ModPlug again then played again, ModPlug crashes
Pretty much sounds like this (http://bugs.openmpt.org/view.php?id=161) and that (http://bugs.openmpt.org/view.php?id=204) - I couldn't reproduce this problem on any computer yet, though. It might help to use an ASIO driver (f.e. ASIO4All (http://asio4all.com/)) instead of DirectSound in OpenMPT.
sounds more like the second one... I am not using any VSTs
The first report was also reproducible without VSTs, so they describe the same problem in fact (i.e. they are dupes).