YouTube audio randomly stopping - Windows 7 Home Premium

Recently, I've experienced issues with audio stopping on video sites, such as YouTube. There are a few others, but I don't remember which ones they are currently. I'm running version 24.0.0.221 on Windows 7 Home Premium. Sometimes, it stops after 30 seconds, sometimes 8 minutes. Normally, it'll run for maybe 30 seconds to 2 minutes and then cut out again. This happens on both Firefox and Chrome, as well.

I've uninstalled and reinstalled Flash, to no avail. Has anyone else had this issue? Am I missing a step, or did I do something wrong?