OK, so all the good stuff I read about 1Password was apparently 1Password 4, as you've just rearchitected. A lot of your support information for Windows is irrelevant if you've started off with an account, so if you're able, going back and making it really really clear what article is for what platform might save you a lot of support time.
Anyway: I have 1Password 6 and it seems to be remembering passwords just fine. Not sure yet about filling, as my browser is also remembering and I'm not going to turn that off just yet.
There are several things you could do in 1Password 4 that I am very much hoping are on the roadmap for 1Password 6.
Do you have a userguide yet for what is / is not available in 1Password 6, and if not available, when it's scheduled? I'm not sure I'll stay here if it's this low-featured.
1Password Version: 6.0.245d
Extension Version: 6.0.245d
OS Version: 7 Enterprise SP1
Sync Type: 1Password account