ID Safe - Auto login to Facebook

Whenever I go to the Facebook login page (http://www.facebook.com/login.php) for the very first time after I've switched on my computer, Identity Safe does not autofill my Facebook login id and password -  I always have to go to the Facebook login page a second time before it autofills.  Thereafter, if I go to Facebook again later in the session, it autofills correctly.  This only seems to happen with the Facebook login page - if I go to any other website login page after turning on my computer, ID Safe autofills it ok.

Does anyone else have this irritating little issue?

I'm on NIS 2012 running under Windows 7 (64-bit), and my browser is the 32-bit version of IE8 (as Norton doesn't seem to work with the 64-bit version of IE8).