I tried the Mozilla because of the IE security problems too. I liked it fine with the high speed, but it doesn't work with this dial-up service I have. I'm still waiting on the modem for dsl. Also, my pop-up stopper wouldn't work with it either. So, I went back to IE, for now.
I've been using this browser for over a year with great results.
Don't know about the dial-up as I have cable modem but the pop-up stopper included in Mozilla works perfectly on the version I downloaded. I even uninstalled the pop-up stopper I was using since it is no longer needed.