Windows 7 - WMP12

Ok so say i'm playing a song and its only one minute into the song when it starts playing another song but the name says it's playing the previous song, it plays for a few seconds then changes back the previous song. I've been having this problem for a week or two now and havent found anything on it that has fixed it, i delted the app data files let wmp create files but still does the same. Help pls.
(WMC does this also, sometimes.)

Sounds more like the audio files themselves are damaged in some way where WMP is only assuming the end of each has been reached when moving onto the other. With different playlists for different groups you will see WMP jump back a few but only when the track inplay reaches the actual end.

This isn't with all tracks however but how WMP is apparently rearranging it's own order of playing tracks as it goes along when seeing this. Tracks played more frequently are being separated from those that sit unplayed apparently being played in an order of WMP's automatic preferences.

To see if those files are damaged you could try playing them with another player like VLC just to see if they play all the way through. If they stall or sound distorted, damaged part way through then you know they would need to be replaced.

You could try defragging the HDD, but I doubt this would really be the issue. It sounds like the files are damaged. I'm not sure how this happened but your drive could be developing bad sectors, which happen to some hard drives with time. Usually, not to many sectors become bad. HD Tune can check your hard drive for bad sectors if you want to check.

ty very much for the advice, i will try both of your ideas and write back to this forum thread. thnx again.

have you got the crossfading settings turned up to max by any chance?