Audio track of some .WMV files plays in lower pitch

When I try to play some windows media video (.WMV) files (videoclips), video is OK but audio track plays in lower pitch (so the female voice sounds like male one). Example info (from Windows media player 9) about audio track of .WMV file, which plays in this manner: WMA 9.1, 48 kbps, 32 kHz, stereo (A/V), 1-pass CBR. The same info for .WMV file, which plays with good audio: WMA 9.1, 64 kbps, 44 kHz, stereo (A/V), 1-pass CBR.
The problem is independent of the player used. My system is Windows 98 SE. Other media files plays good as well. Any idea ? Thanx. Petr