Is this an example of a browser redirect or intrusion prevention?

This is similar to another question I posted, but different. So that is why I post as another issue. If I am incorrect in doing this let me know.

 

I use Desk Top PC with Vista Home premium, IE7, Norton AV2008 as my real time security and Malwarebytes, Spybot and windows defender as on demand scanners. I log on the computer with a limited user account

 

Sometimes and I stresss sometimes, when we log on  to facebook and then click through pages ( friends pages not ads) sometimes a box will pop up looking like it might be from windows The message says

 

"Internet Explorer cannot open this page"

 

Having gotten a little smarter over time, we then close out using task manager. Then when we click IE7 again and then log into facebook, we are able to proceed without issue.

But when we look into the IE7 history tab, we will see the entry for a website we did not click on or go to ( example getsabout.com or some other website known for malicious behavior)

We have been keeping track and it seems to only happen on facebook and then not all the time. Sometimes days will go by without this being an issue and it only started happening 1/20/10. And we are on facebook multiple times a day everyday

I have checked the host files (C:\Windows\System32\Drivers\Etc) and there is nothing in there except the examples they give

So is this a

1. Drive By download attempt?

2. Browser redirect?

(if it were a browser redirect, wouldn't it happen everytime we use the browser? Or at least when we use the browser to go to oother sites?

3. A problem in the host files?

4. Or is it just a combination of Vista, IE7, and the intrusion prevention function of Norton stopping anything from happening?

 

Norton logs show nothing about blocking or any security activity when this happens

 

All scans- Norton,Spybot, malwarebytes, and windows defender all come up clean when we run them after this activity occurs