iTunes Not Reading m3u Files Properly?

Hi people.

For the last few months when I double click on an m3u file to import a playlist to iTunes the songs appear in a new playlist but as I play the tracks, anything longer than 4:13 jumps to the end of the track at that point (4:13).

If I import each track separately by double clicking on the mp3 file there's no problem playing the entire track.