The specific ad in question was a flash ad with holly "growing". It was in the top center of the pages. It has been off the site for at least a week.
Teh Fixer determined it had bad computer code in it, from the advertiser. That code caused the entire holly show to complete itself before anything else could continue loading. All normal flash ads load without requiring the entire ad to "run" before other site content can load.
Again, the bad ad is dead and buried.
I certainly sympathize with those who can not purchase high speed connections in these times of image laden websites. It must be terribly frustrating.