Help wifi stops when sim card in


hi All
I have a nexus 7 which works perfectly with my home wifi, after I put my sim card, the mobile network does not turn to data mode and even wifi stop working. then I remove the sim card and wifi continue not working until I do the reset factory. the message is ( not in range ) or (saved, connection ) for wifi.
does any body know this problem.? another problem is how can I access to my sim card setting to config data and proxy of sim card manually?