So far I have no solution, but do have the same problem. What I can say about my situation and what I've found is that it does not have to do with the browser. I am using Google Chrome and the only correlation that I can find between us and the others having this problem is the Adobe Flash Plugin used for alternative browsers (alt to IE which uses it's own plugin via activeX). This problem just started happening, maybe 3-4 weeks ago. I do not recall doing updates on flash or my browser, but it was around the same time as Cypher.
My computer is a 2009 Macbook Pro 13" with the Cirrus Logic CS4206A High Definitio sound card. This computer runs Windows 7 primarily and this is where I am having issues. The research I've done has shown this same issue is occurring within Mac OS X with Firefox as well. More info @ http://forums.macrumors.com/showthread.php?p=9379950&posted=1#post9379950
I too have tried everything short of a full system restore. I know it is not an issue with my OS or Drivers at this point. I have stripped down all Boot Camp (apples drivers for windows) software from the machine and reinstalled with the latest updates twice now in the past week to no avail. I have tried alternate sound drivers (those from the sound chipset MFG and MSFT) and have downloaded the beta version of the Flash Plugin from Adobe Labs at a bloggers recommendation, all to no avail.
The situation for me is this. I love Google Chrome and never want to switch. But much like the iPhone and iPad, I need Flash. Now I know what they will say. "Google Chrome is not officially supported by the Adobe Flash Plugin. We at [insert adobe's name here] are genuinely excited about the prospects that Google Chrome brings to the internet and look forward to supporting it in the future. Please check back often to see our continuing releases for updates concerning Google Chrome." or something like that. Luckily for me the problem exists cross platform with a number of browsers. I believe this is a problem with the Adobe Flash Plugin and certain type (or just one type?) of sound card.
But to get you through, I've been able to do this. When I have this problem with the Flash Plugin (Firefox, chrome, etc) it effects all sound on my machine. If you close your non-IE browser completely, all windows, and open IE (I know I hate it too), it will use the ActiveX version of Flash and it works fine. Try this for yourself and let us know with a Reply here what you find. I also think it would be helpful to the diagnostic process for everyone to post what they've tried and what sound card they have in their systems.