It has to do with the link on that banner opening up another window- i.e. a pop-up.
If you view the source on your problem browser, you may notice that the img tag for the banner has been replaced with some funky looking code.
I don't remember the fix, but if you Google the funky code, you should be able to find it. If you need help figuring out what the funky code is, let me know.
I think I would need alot of help on that. Do not know if it makes any difference but I am running Windows Vista and it has been more of a
pain in the neck. I am at work now and the banner is fine, this is just on my home PC.