WordPress MU

I just had a weird thing happen:
went to one of my users blogs, noticed he had inputted google adsense code into the default text widget and the ads were displaying on his site.

THIS should not be possible.

So I searched a while, and it seemed I had activated the mu-unfiltered plugin for this blog. After deactivating it, the google adsense ads disappeared from his sidebar.
I thought, good, now at least I know why he was able to do this...
I enabled the mu-unfiltered plugin again for him, but the ads won't show up again...

Any ideas whats wrong here? Was the mu-unfiltered plugin to blame? Why would it not display the ads after enabling it again?
Does this plugin even apply to the widgets?

Do you know that it takes some time for Google ads to appear after a code is inserted?

Well, in my case I insert a code, wait 2-3 minutes and refresh a page. You won't see Google ads immediately.
Maybe that's your problem :)

hmm... can you quickly check? http://sasha.zice.ro - do you see any traces of adsense in the sidebar?

No visible traces at the moment.
But when viewing page source - pay attention to line 99
I see this:
<p><!-- google_ad_section_start --><img src="http://lh5.ggpht.com/neliniste.metafizica/SLLqLXRdTiI/AAAAAAAAAQw/006LPHqAqxs/s400/S7303548.JPG" alt="" width="552" height="384" /> Read more » </p>

thx.

I guess he copied those in by mistake!?

anyway, in the source code of the sidebar, I see, just below this: <h2>Administrare</h2> some adsense code... but am behind weird proxy, that's why I asked if you can see anything...