I have been playing with OS X Lion update for a while now and amongst the little things here and there that do nto fit in well, I figured out that Google Adsense ads dont show up while browsing! Now, I ain’t a person who runs Ad blockers, worse, the ads weren’t showing on my own site when I first took note of this. A quick cross check on Chrome and I realised that it’s the Safari that is causing issues.
A quick google search showed resolutions for issues that block Adsense or other ads across all browsers, but nothing specific to my issue. Luckily just playing around a little with Safar Extensions did the trick. Yes, you may throw the conspiracy theory of Apple playing bad with Google out of the door.
So if you updated to OS X Lion and facing the issue of Adsense not showing up on Safari browser, here is the fix.
Head to Safari Preferences:
And look for extensions. The culprit as I figured out was, ‘DivX Plus Web player’ and the DivX HiQ extension. All I did is diable it (uncheck the enable box) and the Adsense ads were back 
We would believe that an update to DivX might fix this, but for now, if you love seeing ads, here is the fix.