Cannot play .flv files with gmplayer (whereas with mplayer it is ok)

Hello,

  -  When I try to open and play an .flv file with command line
mplayer everything is ok.

- When I try the same with gmplayer, I keep getting a message
flickering all the time , saying:
"AO_ALSA: Unable to find simple control 'PCM',0.

Any ideas what should I do to be able to play this .flv with gmplayer?
I want to add that on vlc I have some problems with unclear audio when
playing these .flv files; and in
totem I cannot play that .flv.

So in this occasion - can anybody recommend an .flv player?

Regards,
Mark