I had a similar problem on my 04 e320 4matic wagon. (no remote starter though) It turned out to be the Crank shaft position sensor...$250 fix at non-dealer. Check out benz world forums for other similar probs/fixes
Thanks, but I guess I didn't make it clear enough that the starter will not crank the engine over with the key. The starter itself is ok 'cause it woks if you enable it at the starter solenoid. I narrowed the problem down to the starter lockout relay module which is located behind the left side of the dash. It may well be a function of the antitheft system which is not allowing the starter to function but at this point I plan on wiring around the lockout relay. The Canadian models were produced without the lockout relay, I guess they don't steal cars there. They are really polite.
I just recently had a similar problem when I stopped at the gas station. Everything worked, but the car wouldn't crank. I disconnected the battery for about 5 min., then reconnected. The alarm system went off, and after I reset the alarm the car started fine.
I have a 94 E320 will not crank over. If I hook a remote starter button directly to the starter it cranks and starts but it will not start with the key. Did this sound like the problem you were having with your car and what did you do to fix it?