I have had this problem for a while, it's mainly with Trials HD (+map packs), and Gears of War 1. The account which purchased the games is the one which I'm using now, the membership on this account is silver. When I went silver I created a new account and made that one gold, and began paying monthly for Xbox live on that.
Here's my issue: On my 'new' Xbox Live account I am unable to play the games which I PURCHASED on my other profile.
How can I fix this?