Quote Originally Posted by TheFirstKel View Post
Try check if the "Direct Chat" option is enabled - which could cause all the key pressed directly going to the chat box.
On PC, when Direct Chat is enabled, think you have to hold the CTRL key to over-ride it when you want to use movement keys (forget the details, I use a PS2 controller on PC). It may require the same thing on the PS3 if you want to use keyboard for movement as well.