Does anyone know if this encoder works with 24p, 16x9 footage? I am having some issues and not sure if one of these factors could be a problem.

Yep, it does (both xvid and divx)! 24p shouldn't be any problem (frame rate isn't an issue, and both progressive/interlaced are supported). Keep in mind that 16x9 is regarded with a 1.0 pixel aspect (rather than DVs 1.2ish pixel aspect). What problem are you having?

I found the issue about 3 pages deep in a google search. For some reason there is a bug that when the Xvid status window pops up it locks up Premiere. If you do into the advanced options and into debug and un check the status window it runs just fine.