Text in Photoshop

[GoldTrader]

When I try to type a piece of text in Photoshop, the only characters that appear are question-marks. (?) For example, when i type: GoldTrader, the following appears: ??????????.

How can i fix this?

 

[Kinaesthic]

Could it perhaps be the font you are using? Some fonts do not support certain characters, does this happen with every font and what version of photoshop are you using?