Hi David,
I might have some for you. I know I at least have one that never worked. I have some others I remember I had to work with a lot to get them to work, but if they fail today I'll send them over. I'm going to play the O2 today and when I do I'll test all of my games to see if any are bad and will send them your way.

Alex
ETA: Only one bad Keyboard Creations, the rest are good. If I ever have any other non-working carts I'll send them to you.