Im not hijacking here, but i have a similar problem, might be related.
when i open media player, it opens quickly, fine. But then i double click on a song in the library to play, and it freezes for a good 5 seconds before playing. running media player 10 on windows XP pro. 1.8Ghz AMD sempron, 80Gb HDD (19GB used), 512Mb ram. by my reckoning, most of the time i dont come near using 50% of this. couple of explorer windows open, media player, msn messenger, internet connection, antivirus.