finally fixed this a few weeks ago. It was both the Ip gasket and the oil filter housing gasket. Heres some tips:

1. You'll need a 6mm allen head to get the filter stand off.
2. 24mm wrench for the oil cooler lines (probably need to grind it down to a narrower dimmension)
3. Mark the IP location so you dont have to re-do timing.
4. Allow lots of time. It took me all day, including the trips to the store for the tools.
5. reinstall the long middle bolt on the oil stand first. otherwise, there wont be room to get it back in later.

My problem was not a failure of the IP gasket; there was no trace of gasket material on it in the first place! Prior owner, it seems from other locations, did not believe in gaskets.

Leak free in 03!
Paul

__________________
Paul
2004 E500 4matic; 72,000mi