Problem with ie7 crashing with flash6.ocx and mootools?

I noticed that my site has a very poor conversion rate for users using ie7. It is about 1/2 the conversion rate of ie8 and ie9.

I setup a brand new fresh install of windows XP SP3, and installed ie7  to do some testing.
When I go to my site, 2-3 pages in ie crashes completely. I removed my  reference to mootools (1.2.5) and I don't have the crashing issue.
I then added mootools back and disabled the Flash6.ocx addon that  comes with ie7, and everything was fine.

My stats show a very small percentage of our users are using Flash 6, But the overall ie7 conversion rate is really low.
Any thoughts on what could be causing the problem with the Flash addon?

I was thinking it may have something do do with page unload, since it  never happens on the first page load.  If I refresh the page, it always crashes 1-2 loads later.