Yes. Google knows about this issue.
- Log into your Analytics account
- Click into the Content section
- Click into the AdSense sub-section
- In the right pane, click "Why do these numbers differ from my AdSense account?"
It will say "Your Analytics numbers may under-estimate those in your AdSense account. The actual differences are shown below."
Then, it will show you how these four metrics from both AdSense and Analytics:
- AdSense Revenue
- AdSense Page Impressions
- AdSense Ad Units Viewed
- AdSenseAds Viewed
Google appears to still be a bit shy about explaining why this behavior occurs.