Audio problems

Hi,

When streaming videos (all online videos/players) I sometimes lose the sound. The sound -disappears when I try to skip ahead in the video and it needs to buffer again. (And it doesn't happen every time i skip ahead, but probably 50% of the time)

I can bring the sound back, by going control panel>>Sound>>Playback (NVIDIA High Def Audio)>>Properties>>Advanced and then pushing the "Test" button. Sometimes I have to push the test button a couple of times, but ultimately the audio does come back.

I'm not going to waste your time guessing what the problem might be, so i'll just provide all details that I think could be relevant...

Windows 7 (64 bit)
NVIDIA High Definition Audio
Geforce GT 640
Connected to Samsung TV via an HDMI connection

Anyone that can help or might have experience with this problem would be greatly appreciated!

Thanks!