mplayer playing avi and wma files too fast

[Jose Maria Pagan Galan <josepagan@xxxxxxxxxxxxx>]

the other day i installed mplayer in FC2, for some reason it plays avis
too fast, just like pressing down a "fast foward" buton.
It works well playing mpeg and mp3 files.

The installation was done with yum install... (livna repositories) so
that should be ok
I use a M-audio audiophile sound card(Envy24chip) working with alsa
drivers.

thanks in advance :D