Yes, we have pop-ups on MW. A lot of sites these days, due to the advertising downturn on the Web, have to run them to make any advertising dollars from "bulk" ads. However, for the most part we keep them off the forums where they would be the most annoying. Furthermore, you are mistaken about all Mustang sites not having them, since there
are other mustang sites that have pop-up ads too. Unfortunately, the operation of MW cost a LOT of money, and also takes a great deal of time and effort, and we have to use them at this time to generate revenue.
My suggestion is that if they personally bother you that much to take 7DMACH1's suggestion and install a pop-up ad killer program. They are freely available on
download.com.