I have come across such a weird problem and was bugged like hell. Past 2 months, I was unable to see google ads on my site, I just though that google might be upgrading, but the problem began to persist. I checked my friend’s blog, the ads wasn’t visible there also so I again thought that its the problem from google’s side. After a couple of weeks, the problem began to persist. I was worried. Start googling. No solution . Then after a long time, I opened my site through a cyber cafe and the ads were vidible on my site, got relief. I came home happily and was surprised to see that the ads were not there. Got frustrated
I was not sure that my adsense was banned or not. Googled for this problem like hell but still no results. Seeked help from google adsense forums but still din’t get proper help. Finally my hope of finding the solution had really bought colors ! I found it on some forums, don’t remember the name of the forum. Some virus caused that problem in my PC.
Well I would like to share this wonderful solution to this problem to you here. This work is of anti0-virus which edits the host file of our windows to block ads from google. This file is located in C:\WINDOWS\system32\drivers\etc\hosts .
Open this file using notepad and check for paged2.googlesyndication.com or any line which is related to google and delete the line completely. Save the file and exit and re-open your site and the ads has to appear there !!