40D and 420EX no custom functions

I just noticed this the other day when playing around with the 420ex flash that i cannot set any of the custom functions for external flash. Is the 420ex compatible with the 40d?

2005GLI,
With the 40D and the 420ex you should be able to set the curtain sync, FEC and metering. However the custom functions (C.fn) are not compatible the the 420ex (the 420ex doesn't even have custom functions) the 580ex does have custom functions but can't be accessed from the camera menu either. I believe only the 430ex and 580exII can have custom functions set by the camera.

well that answers that question. thanks.

Its strange.
As John says, you can set the curtain, sync and metering with the 420Ex but i remember a thread ages ago where people couldn't do this with the 430EX.