Firefox keeps flickering. . .

So I turn on my crap computer today just like I o everyday and open Firefox, about 30 seconds after opening I open my bookmarks and it flickers for a second. I'm like "Okay, minor glitch."
I open Seven Forums and I sign in and click the general discussion link and Firefox says "Not Responding" and goes white, then when it comes back I click general discussion again and Firefox flickers again, then I click a few more times with flickers until it finally opens the General Discussion page.
So I open another tab, "Not Responding" for about 10 seconds and I open Cnet, and I click on the Seven Forums tab and it flickers again, clicking a few more times with flickers until opening the Seven Forums tab.
So I keep getting flickers when I click a link/tab and random times when it goes to "Not Responding" for about 10 seconds. I thought a reinstall would work, but add-ons are a (female dog) to install.
It seems Firefox becomes more and more worse as the version number increases, any help?

Yes, I'm using a current release version (3.6.13).
I closed and re-opened Firefox, it seems to have lessened the amount of times the problems consist, but I still get the problem here and there.

Hi, again, PwnFrnzy. :)

Have you attempted to use a fresh profile?

Hold the "Shift" key as you start FF and select a few options available. Sorry, I'm tracking the BCS game right now and will present a screenshot and a bit more information after the game is over.

Congrats to Auburn ... great game! :)

PwnFrnzy, try "Continue in Safe Mode" and see if the issue persists. If it doesn't, you'll need to disable your add-ons one at a time (or disable them all and re-enable them one at a time) until the issue is no longer present, or returns, depending on the method you choose. You will then have found the culprit.

Or as suggested before try creating a new profile. Here's a tutorial- How to Create a New Profile in Firefox | eHow.com
Have you recently installed any add-on or plugin after which this started to happen?

No add-ons or plug-ins were installed before the problems, I however had been using a cleaner called "Advanced System Care" ans had reversed all of it's changes due to it's questionable Registry cleaner/editor. I then re ran it to see if the problems would b4e resolved but it's still glitching and has started to open new Firefox windows randomly on the tab that I'm working on/viewing.
I have tried the two options you have both presented, but both have also failed.
If re-installing Firefox fails, I believe that a clean and re-install of Windows would be the only way to resolve the problem.

A pop-up does not come up, I always have multiple tabs open while browsing, then I would click on one of the other tabs while Firefox flickers into a seizure, then a moment later the tab Iwas trying to switch to would open in a different Window. I've been on for 5 minutes so far and there has been no issue. If it comes up again I will do the re-install, since my last post was made while I was at school.
But I will run a scan with Malwarebytes anyway to see if something comes up.

I doubt I will get a "masterpiece" signature like you said, but hopefully I will get lucky.

It seems the problem has disappeared, it's been almost 2 hours and the issue I previously had is no longer coming up, odd.
Thanks for the support!