Sim card not recognized!!

[limited733]

Hi to everyone! I recently bought an unlocked Diamond from Germany. I have tried several sim cards on it and each on works but when i try my greek cosmote sim card it shows an icon sim with an x on it and sazs sim card is missing, that means it doesn't recognize a sim card is inserted. When i try this card into a TyTNII that i own there is no problem!! What can be my problem here? The phone is for sure NOT locked to any network!! Thanks for any answers!

[mugglesquop]

it could either be a problem with the Radio not supporting the network (someone else may know more about the bands than i do) or a problem with the hardware, in which case, send it back to where u bought it (if possible).