How to change from Infastructure --> Ad-Hoc?

I have this printer (Brother 640-CN) that supports wireless b/g networking. I have a wireless G belkin router. Now my problem is that the printer wont get deteched by the software over wireless (wired no problem). ive set the printer mode to wireless and config my ssid/wep to the one according to the set up. However, i am not sure if im running infastructure (probably am) or ad-hoc, i see no option in the 192.168.2.1 (yes its a 2, belkin made it this way) any tips?