iTunes Account on an external bootable drive???

Hello,

Before I upgraded my iMac to Lion, I created a Snow Leopard bootable external drive so I could play a Star Wars game that was not compatible with Lion.

There are a few items in the Snow Leopard and I had to authorise them to play - which indicated to me that this bootable drive was considered a separate machine to to the iMac.

I have the Snow Leopard drive running on my mother's MacBook (which runs on Mountain Lion) at the moment.

I was trying to download a few old purchases in iTunes but I got a message saying the device is already associated with my mother's account and I cannot download my music.

I don't have the iMac here to check, but I am fairly certain that I have never associated the Snow Leopard drive with any account.

Have I done something wrong or is the Snow Leopard iTunes associating with the MacBook's iTunes account because the Snow Leopard isn't a "real" device?

When connected to my MacBook will it associate with my iTunes account?

Is there anything I can do?

Cheers