there are several other possible programs to prevent pop-ups..one that gets a lot of comments is Naviscope ....it does other things too, and for now is free...(also other possible programs at Pricelessware
and more pricelessware, just a different place in the page
the Pop-Up Killer program is listed here, so it must be ok.....
now, I have to try ONCE more to install PalTalk