If you download and install it, it prevents all popups! I checked the box to disable advanced features.
You will see a tool bar underneath the url address box and in the middle towards the right it will show you how many popups have been blocked. Right now mine says 702. If you are at a site where you want popups, i.e. alpha trade, you just click on the spot where it tells you how many have been blocked and it allows popups at that site only.
I was told about it by my tech at work but I'm pretty sure Matt has spoken about it also. So far I have not had any problems since I installed it. I don't know if there would be if you install it and enable the advanced features.