Ok, I'm experiencing a problem with connecting to my friend online and joining his party or w/e for halo 3. I've played fine with my other friend but every time I try and play with this one specific friend it says joining for about 20 seconds, then it says unable to join, the request to join has timed out.

Help? Suggestions? Thanks.
My Rig:

Schecter C-1 Classic (Deep Sea Green)
Jackson DK2M Snow White Edition
BC Rich Mockingbird Special X

Mesa Boogie Express 5:50 212
Roland Microcube

RIP Kevin Robert Swerdfiger
September 15 1991 - May 16 2008