I'm new to the Mac world and tried both MSN Messenger for Mac (7.0 and 8.0 beta) as well as Adium to connect to the Windows network. I've enable 'Allow all incoming connections' in the Firewall settings. Windows Live Messenger works fine when connecting through the same router on my Windows laptop. I've triple checked my password and verified it through a web browser and Windows Live.
Any ideas what my issue could be?