SMTP Mailer is KILLING me

Folks, the first person to figure this one out will make my day. Let's just say I've tried everything for the past few hours, and I've become frustrated to the point of forum-posting. So...ready? Here goes...

I keep getting this error: "553 This SMTP server requires authorisation. The password you've entered is incorrect" -> http://pastie.org/326542

Only thing is the password IS correct. I checked with my web hoster. So I began some trial and error...like deleting the smtp information from the development.rb page. Nothing happened - same error.

I'm really stumped. Here's everything I'm working with.

-> My "signups" controller: http://pastie.org/326541 -> My development.rb file: http://pastie.org/326538 -> My mailer: http://pastie.org/326539 -> The associated view: http://pastie.org/326540

Please - any help would be greatly appreciated.

Cheers.

one dumb question, and this has caught me before, you are restarting after changing settings?