No sound on some channels

Hi,

kdetv works fine for most channels, but it looks like it mutes sound 
automatically on channels with bad quality.
I receive some channels only with bad quality, but it's still good enough to 
watch and because the signal is very unstable i sometimes get sound for one 
or two seconds then it's muted again.
I have a WinTV Go card (mono).
Is there a way to remove this automatic "bad-signal-muting"?

Thanks, impic