For years I've had a WindowsXP-32 bits on which was installed a Canon MP210 printer. This printer was shared to be used by the Ubuntu of another computer. In CUPS, the url of the printer was "smb://192.168.0.2/canonMP" and it worked like a charm. As far as I can remember, that's the only thing I had to set to share the printer.
Just this weekend, I've upgraded my gear and replaced my WindowsXP-32 by Windows7-64 and I'm having troubles with printing from Ubuntu.
Since I'm a bit new with Windows7 and 64 bits systems, I'm not sure which direction to investigate. 64 bits drivers for Ubuntu? An other protocol than CIFS? One sure thing is that the firewall of Windows7 isn't responsible: I tried printing a test with the firewall down and it didn't work. I also correctly set the share name of the printer.