I been having a freezing issue too. I can't say for sure that it's happened because of the downloading of TBoGT, but I've only noticed it since then. Here's a link to my thread about it... I didn't see your thread before writing that one.
http://forums.xbox.com/29886335/ShowPost.aspx#29886335
Me:
http://www.Myspace.com/JMCatrowMy Band:
http://www.Myspace.com/ByDemonsBeDrivenBand