[otrs] Problems whit user privilegies

Hello, I just installed OTRS system on my computer but I've had some problems when I want to watch tickets. The thing is I login as a customer (asociated to an specific group)and add a message (ticket) to certain queue (related to the former customer group), then I login as user (again, related to the right group too) to read received tickets but I can't see them, so I have to login as admin and change the user privilegies to RW, once I've done this I can see added tickets. I think that should be possible just having RO (read only) privilegie, it shouldn't be necessary to set up RW. Help me please!!!! PD.: My english is terrible, sorry. Patricio Tello Aróstica