I have an HP scanner with an SD card that it shares over the network. It requires no username or password to access the files. I connect to it daily with a Windows 7 PC without problem.

I try to use Ubuntu's Nautilus "Connect to Server" feature to connect to it by IP address and it requires a username, password, and domain. I provide "guest", "password", and "WORKGROUP" as the values. It connects and I can list the files, but if I try to download one of them, I get a "permission denied" message. Funny thing is, I can rename them. I just can't copy or read them.
Ideas? What can I provide to help clarify my problem?