Sorcha...the popups, of course, are not 'on' Mudcat, just 'during' Mudact. It seems you need someone who really know this s**t to sit at your PC and explore.

Obviously, there is some kind of setting not set right yet, or hidden executable...whatever...that is unlatching the door for these things. (possibly being RE-set daily some remnants of a progran dear daughter downloaded.) Remember..these folks work HARD to not be discovered, and they know lots of tricks!

You said way back up there..." I also downloaded Outpost Firewall, but it didn't seem to do much of anything for me so I uninstalled it"...does this mean you are running with NO firewall now? If so, all other steps you take may be just swatting at flies when the hole in the screen is still unpatched!

I will also ask if you ever tried or considered the program that I have recommended somewhere else...The Proxomitron

between a firewall and The Proxomitron and Opera (or Mozilla/Firebird), I do NOT get popups, and 'almost' no ads on web pages.

It is sad, but in this day & age, you either learn to control spam, hire someone else to do it for you...or keep manually closing pop-ups and wasting time & energy.