Forum Moderators: open
I suspect it's the update thing - if your site is clean (ie, no tricks).
Many other people have mentioned the same problems since the Dominic update started. Both the problem of PR going to zero and of having some or many of their pages dropped from Google. I'm in the latter boat. Fortunately only a small portion of my pages have been dropped.
Beth
You are not alone. We have a site with the same situation (completely clean site, non-commercial). It was partially indexed in February, and fully indexed in March (PR4). Dominic kept only the index page.
What I find particularly frustrating is that freshbot comes regularly to this site, but these pages are never added.