I am having the same problem with the latest version of ALL IN ONE SEO (Version 1.6.13) and I use TwentyTen too.
Does this not work with TwentyTen? Or does it just not work at all?
I take it I've installed it properly as I'm new to this and havnt ever installed a plugin before (simply clicked install and then simply enabled it)
I went to
SETTINGS>ALL IN ONE SEO
and Ive tried changing the Home Title/Home Description and hit update options etc but my TITLES stay the same as whats written in
SETTINGS>GENERAL>Site Title & Tagline
My site is pretty damn basic and like I said it has no other plugins so I cant see how it conflicting with anything.