Ok, on the CPU use thing, we have identified a problem with the NewEgg 120x600 ad and have requested a fix. That should rectify that problem.
As for crashes, do they persist? From what I gather, the problem only comes with the magical combination of Firefox, the AdBlock extension, and the Flash extension. Right? And only on the main page of the site, and only intermittently there? Please confirm all of this, and I'll see what I can do to isolate the problem.
Oh, and forgive me for dragging my feet on this. I've been terribly busy, and frankly, for a while I thought the problem only affected people blocking our ads. I would pay to purchase a tool that would crash the browsers of those people, so you can see my lack of motivation.