I recall there being a thread devoted to a rather simple opt-out option for pop unders. It's something that I ran on a previous computer, but that computer is now spare parts, and I'd love to run it on this one.
However, I can't seem to find said thread. I've done a Google search on The-W. I've perused the Internet & Computer forum here. I've even dug through CRZ's World, because I think he mentioned it after it had been around awhile.
The part Guru is talking about is the PRAM battery. Instructions for resetting it can be found here. But, given the symptoms, you probably will have better luck trying a reset of the "Cuda" a.k.a. the Power Management Unit.