Obviously I was stupid not to check this earlier but anyhow, this week I started checking on the Adsense performance of one of my sites and found that the Adsense plugin/module I was using on the Joomla site wasn't passing along impressions and Click throughs accurately since Adsense changed to the ad units.
I changed it this morning to hard coding the adsense code and in 12 hours I had 25% of the month of July's impressions.
I changed another site as well and within hours had more impressions and click through than ever before.
I'll be watching this to see but it seems that I have at least 50 sites to change!
Even at conservative calcutations I've lost, well, not a fortune but a good sum over the last few months since Google changed to the ad units.
I'm "looking forward to" doubling my Adsense income virtually overnight!
If you are using plugins to populate your site's Adsense, check that you are getting the credit, especially if you are using the same plugin you used before the ad units came in!