Absolutely. The authentication box comes up and I enter in my username and password (which work when I connect from a Windows box), however the box shakes indicating that it can't authenticate.

Am I really the only person having problems with this?

I can authenticate from any Windows box with various different usernames, but from my Mac I can't connect at all unless it's as a Guest, and the shares allow Guest access.

After countless searches, and many hairs pulled out, I'm being forced to come to the conclusion that the SMB authentication in Lion is borked! The only way I can access my Amahi shares from my MacBook Pro with Lion on it is to use Guest access. I can access the same shares from various Windows boxes...