Lorsan

I purchased the keyboard on 8th September from a local retailer here in the UK, although it wasn't used until a few days ago

Hi all, I recently bought the Challenger Prime keyboard, however I've encountered a problem with a couple of the keys. I cannot capitalise T or X using the shift keys, and have to use Caps Lock instead for these letters. I also cannot access the speech marks (Shift+2 on UK layout). The shift keys work fine for all other keys. Have I been unlucky and gotten a defective keyboard, or am I just being stupid and missing something obvious? I've tried different profiles, downloading the relevant software etc but the problem persists