Could be Windows Messenger spam, too ... hadn't thought about that. See this
Article about the critter.
If you have AdAware, you can download Lavasoft's
Windows Messenger Control plugin.
GRC, Steve Gibson's great website, offers the free
Shoot the Messenger which does more or less the same thing for those without AdAware.
Windows Messenger can be disabled manually in most Windows versions:
Windows XP Home:
Click Start->Settings ->Control Panel
Click Performance and Maintenance
Click Administrative Tools
Double click Services Scroll
down and highlight "Messenger"
Right-click the highlighted line and choose Properties.
Click the STOP button.
Select Disable or Manual in the Startup Type scroll bar
Click OK
Windows XP Professional:
Click Start->Settings ->Control Panel
Click Administrative Tools
Click Services
Double click Services Scroll
down and highlight "Messenger"
Right-click the highlighted line and choose Properties.
Click the STOP button.
Select Disable or Manual in the Startup Type scroll bar
Click OK
Windows NT:
Click Start ->Control Panel
Double Click Administrative Tools
Select Services-> Double-click on Messenger
In the Messenger Properties window, select Stop,
Then choose Disable as the Startup Type
Click OK
Windows 2000:
Click Start-> Settings-> Control Panel-> Administrative Tools->Services
Scroll down and highlight "Messenger"
Right-click the highlighted line and choose Properties.
Click the STOP button.
Select Disable or Manual in the Startup Type scroll bar
Click OK
Windows 98 & ME:
Windows Messenger Service can't be disabled manually, as far as I understand. I've heard of a couple pay-for products that claim to do it, but I have never tested them myself, so I can't and won't recommend for or against 'em.
Here's a sorta fun PopUp Blocker Test Page some of you might get a kick out of. I don't get much entertainment there, other than a couple of "Attempt Blocked" alerts on one or two of the tests
This is what an A2K (or just about any other) webpage looks like to me: