What is UIPopupHidden and how do I get rid of it?

Every time I try to shut down my computer, I get a close program box that invites me to manually close something called “UIPopupHidden” because it isn’t closing itself.

What is this thing, how did it infest my computer, and why don’t any of the spyware programs catch it and delete it? I want to eradicate it, but it has made itself invisible and elusive.

It’s part of a pop-up blocker.
Remove the last 5 apps you loaded, I’ll wager that takes it out.
Try it one at a time.

Update:
Here’s what appears to be a definitive cite:
http://www.castlecops.com/pstp372446-.html

The post dated:
“Tue Dec 07, 2004 4:55” has the goods for you.

Thanks, but… I don’t have Telus Security Services (never even heard of it). Instead I have Verizon internet security suite.

Which is true, and simply means that you’ve got the same product by the same programmers installed with a different name and logo on it.

I think the real authors are “radiant-something-or-other”.
There’s a long and storied history of client software being rebranded by ISPS.

Telus is a Canadian telephone company and internet provider - Bell provides the same package (which I no longer use as I found it more trouble than it was worth and went back to my previous security programs), as does Verizon.

So that would explain it. Does that mean I could follow the same instructions, only substituting “Verizon” for “Telus,” and expect the same result?