I have the same problem with Contact form 7 and w3 total cache. I’ve never had any database troubles befoe 3.0
I get a “310 (net::ERR_TOO_MANY_REDIRECTS):” after installation and I canät access the site. I use linux.
I have two blogs and I’m having the same problem with one of them, but strangely not both. I use Firefox 3.