vetpeter,
I was thinking the same thing - that this might be a theme related problem. Except I've installed wordpress seo on a clean installation of the theme I'm using and this doesn't happen. I've then combined it with all the plugins I use, one by one, which do no include the calendar or contact form plugins mentioned, and the titles & metas still show up. I have yet to isolate the problem but I think it doesn't occur until I start changing values and configuring the wordpress seo plugin.
One thing I do know is that I am getting javascript errors in my admin dashboard and all the errors are in the wordpress seo sections of the site's scrips.