I use anti-seize on my Ti frame, too. I figure: can't hurt, might help.
To get a bit more specific:
Metal Type of Anti-Seize
========== ===============
Stainless Steel -- Nickel
Brass against steel -- Nickel
Aluminum against steel -- Zinc
Monel, Inconel -- Nickel
Titanium -- Nickel
General purpose -- Aluminum-Graphite
http://www.sacskyranch.com/antiseize.htm
http://www.saftlok.com/safteze/antiseiz/nickel.htm