I have recently implemented a new way to determine the song length in all cases (even with patterns playing backwards and such). This mechanism is now also used for WAV export and general playback. Needless to say, that is quite a big change in the code and I'm sure there are still some bugs that want to be fixed. My biggest concern is the no loop mode (i.e. disabling the "Loop Song" check box on the general tab). I never use that mode myself, so I didn't test it very much, but I know some of you sometimes use it. So I'd like to ask you to test the current SVN version and report any inconveniences with song playback (f.e. song stopping early, song not stopping at all in no loop mode, etc...). With this rather big change, we're also quickly approaching the release of OpenMPT 1.19, so please report any other bugs you encounter as well.
Download the test version:
http://sagagames.de/stuff/mptrack.exe