Man, is that annoying, or login forms that are in a dynamic dialog and/or ajax-login out of band instead of a post, so that it doesn't offer a save option... I mean, I tend to use LastPass over the built-in manager, just the same, it gets annoying when sites work extra hard to subvert those things that make actually using the web easier.

Along the same lines is one of the reasons I actually like OAuth/OpenID/OpenAuth logins, etc... simply that I can avoid yet another login that I only use on one site, with yet another password, that I generate and won't remember anyway.