Custom CSS causing IE to shut down!

We're using IE 6 in most locations and IE 7 on a few of the machines. We do have Firefox installed on all machines and recommend it, but many users just use IE b/c that is what they are familiar with and I cannot control what they use. I deleted the CSS (modified elements of the Minimalist theme) and am starting from scratch to see if I can find what caused the problem and am also now doing all development in IE 6. I also suspect that it is the sidebar script modifications that might be causing problems though nothing crashed it until the CSS went live.

With the wiki.css I have noticed that although I change the "body" font in the CSS editor and it shows in the preview that in the actual pbwiki site nothing changes. Does this mean that even though I purchased the customizable CSS I am still stuck with the fonts from the minimalist theme? I noticed that this is the case for other elements that I change in the wiki.css that don't display in the live pbwiki. I noticed this question in an earlier post but the answer was not helpful.

any reply would be appreciated