I have a similar problem.
I used to connect to the SMB NAS printer server (BlackArmor 110) on which I have my printer connected. Although I can access the disk on the NAS using SMB from my mac, I cannot connect to the Printer using the Workgroup dialog on the add printer menu. Not even the BlackArmor appears under Workgroup. However the rest of my pcs appear there Which shows that there is a small incompatibility with Seagates way of SMB implementation? It used to work flawlesly on Lion! Is there something I forgot to turn on maybe? I did a clean install of mountain Lion but I can't remember ever making a special configuration to use the NAS.
any ideas?
Edit: After waiting for a fix for SMB shares by apple, I installed today 10.8.1 which supposedly fixes the issue with long names in SMB shares. I hoped the problem was the long name of my printer under SMB...
Bad luck... didn't work! DAMN! I'm on ML for 2 months now and can't Print! I mean... it's printing... like the most basic job a computer has to make after "beep"!