I am having trouble with audio when playing streaming videos. My sound card is fine. I know this because if I play sounds from my local machine, there's no problem. It's only when I try to play sounds from the internet that I lose audio. This only started happening recently when I did 2 things:

1. I connected a USB headphone/microphone set to record screencasts
2. I began recording/publishing screencasts from screenr.com.

I have tried playing video both with the headset connected and without it connected: it makes no difference.

If I record a screencast on screenr.com and preview it, I hear the audio. But once I publish is and play it, there is no audio. I also hear no audio with YouTube videos.

I really hope someone can help.

Thanks.

The latest is that the problem went away after I powered my system off and on. A reboot didn't do it, I had to actually shut down the power.