I think the hint is probably in the message .... it's your popup blocker ;-).... the question is which one?
Internet explorer, google toolbar, your malware, adware and/or virus scanner (should they be re-named to virus scammer?) to name just a few.
and they all will have "allow" lists
in IE its tools | pop-up blocker | pop-up blocker settings
in there you can list sites you will accept pop-ups from
read the message ... see which of the possible progs is getting in your way