Why won't OS X Mountain Lion remember smb password on login? After mounting an smb shared drive and putting in my username and password, OS X will ask me if I want to save password to keychain.  I can say yes but it will not save it.  The drive has also been added as a login item.

My username requires the domain, so it's like:
mydomain\firstname.lastname

On login, the window pops up and has forgotten the mydomain\ leaving firstname.lastname and the password field is, of course, blank.

Any help would be greatly appreciated!
You can create a link file with the username and password, and put that in the login items.

In Finder select Connect to Server and enter:

smb://domain\username:password@serveraddress


Don't click connect or press enter, just highlight the whole address and drag to desktop (or anywhere else), and it will save as a file. You can rename it, if you like.

Then from System Preferences, Users and Groups, Login items, add the file you just created.