Upgrade

Hello.

 

I can't upgrade from Norton Security Lite. I have tried several times, Google seems to authorise the purchase then goes to contact the Android Market then I get a message "subscription cancelled". I've tried 3 times and, given the message, I'm assuming I won't be charged. However, I would like to buy the full version.

 

I have just bought an HTC Desire S.

 

I should add I'm completely new to smartphones and I can't see what I'm doing wrong. Any advice appreciated. Thanks.