I had MP 0.2.3.0 running perfectly. ... I installed WinXP SP3 & MP 1.0 RC2. I had problems with a lot of files not playing & subtitles not working
My experience too.
0.2.3 was OK, even though there were a lot of quirks, but it's been downhill since then. Every new release breaks something new.
Ad as there hasnt been any releases after the 0.2.3.0. Many people seem to forgot that all SVN & RC releases are for TESTING only.