40D + 430EX II - AF Assist not firing

Hi gang, I'm having a bit of difficulty... for the life of me I can't get the AF assist on my 430EX II to fire when mounted to my 40D. I've made sure the custom functions on both the body and lens are set properly, but it still doesn't fire. If I stick the 430EX II on my Rebel G film camera, AF assist fires just fine.

Any insight? If its relevant, I recently bought this 40D in mint condition at a local camera shop as an upgrade to my T1i.

Thanks!

Never mind, fixed it! AF mode has to be set to One Shot, NOT AI Servo, for AF assist to work. Hope this helps others with this issue.

Glad the camera is okay, and thanks for reporting the fix, for others who might be in the same boat in the future.