Please help me print to my wireless printer when connected to the internet.

I have recently purchased a Brother MFC-7840W for the sole purpose of wireless printing. I can get it to print correctly under certain conditions. However, when I turn on the internet connection, it changes the printer status to 'offline' and I can't print anything then. I must then turn off the internet connection, disconnect my wireless connection to the router, then reconnect to the router to get the printer status to 'ready.' Once 'ready' I can print anything except from the internet.