Over recent weeks, none of the four browsers (IE6, N7.1,Op,Moz1.4) installed on my system have been showing the AdSense ads, just a blank space. Today, I discovered why. If you're having problem seeing adsense ads on your pages read on...
A browser hijack script had taken the url of my homepage (my own site) in each browser and attached a url of its own (<snip> banner) to pop up in a window whenever I opened my site in Mozilla or Netscape. Also, intentionally or otherwise, it prevented AdSense ads from displaying.
Mcafee Virus Scan hadn't found anything and neither AdAware 6 or Spybot S&D picked up and problems either.
The solution was a program called - HijackThis.
Check the contents of this file:
c:\WINDOWS\system32\drivers\etc\hosts (no extension)
If there's more than one line (localhost), chances are that will be your problem.
If you're having this problem, run the HijackThis program and look for suspicious entries labelled R0, N3, 01. I 'fixed' all of these entries, rebooted and now the problems have gone and AdSense is showing again! >:o))
[edited by: Jenstar at 1:59 pm (utc) on Nov. 8, 2003]
[edit reason] No URLs please! [/edit]