It could be conflicting with another program installed in your case, Rich. I just am not having any issues with 3 computers to the sites I visit.
My wife buys everything online and I fully expected if there was an issue it would show up on her computer.
She is always on sites selling just about anything you care to mention and no blocks.
I just checked the Add Muncher log and in 10 days has blocked 10,488 adverts on this computer so more than happy.
I unchecked installing the Tool Bar on each computer.
No software is perfect, even OS's.:)