Windows 7, 32-bit

Firefox 12, 32-bit

Flash Player Version 11.2.202.235

I'm unable to load videos from many sites right now, and I've done everything else I can possibly think to do except ask for help here. The problem started spontaneously. Nothing seems to have been added to cause this, as it literally happened overnight (possibly during the day, as I have the recollection of running into error messages suddenly, and them never stopping), and even if it had, a system restore should have resolved the issue. It didn't. I've tried all of the following, none of which helped:

-System Restored to Well Before the problem occured.

-Uninstalled Firefox.

-Upgraded to latest version of Firefox.

-All add-ons disabled.

-Uninstalled Flash Player

-Upgraded to most recent version of Flash Player.

-Drivers are up to date.

-Ran through all of Adobe's Troubleshooting options.

There shouldn't be any issue with an ad-blocker, as I don't believe I have one, and even if I did, for it to work perfectly one minute, then stop the next is absurd. Nothing changed with my PC-Cillin virus scanner. I even disabled internet protection completely, yet it changed nothing.

PROBLEM MANIFESTATIONS:

Youtube:

HTTPS Server: Plays all videos & components just fine.

Regular Server:

If an ad preceedes it, the ad never loads, and the skip button can never be pressed.

Can play videos without an ad preceeding it, but cannot load Closed Captions or Annotations (which has a symbol next to the button).

Despite never loading the ad, it lists the file's name, and clicking on it will take me to the ad's own youtube link, which plays fine. That also tells me Youtube's ads are on-site, so where's the breakdown occuring in getting an ad to load?

ORIGINALLY, when this manifested weeks back, Youtube spat out an "Error Loading Video. Please try again later." message. That stopped after about 2 weeks, now it gets to the point where it realizes it needs to load an Ad, but won't.

IGN.com:

HTTPS Server: Plays videos fine.

Regular Server: Perpetual loading ring.

*: Some other sites never load the video or stream at all, even on a Secure Server. The video container is completely empty (Whereas on Youtube it realizes it needs to load an ad, but doesn't).

I'd like to fix this instead of having to switch browsers, but what am I to do? Nobody's been able to offer a solution, and everything I've tried has failed. I see no legitimate cause for this either. What Flash Player problem could survive a system restore and reinstallation of my browser and flash player?

Your time and assistance mean a lot to me. Thank you for any help you can give me with this frustrating issue,

- Jini