I purchased an ID405 about 8 years ago and had a similar problem. It began when I was installing the distributor, I dropped the rotor and it broke into two pieces. So I ordered a replacement and what I got was an aftermarket rotor (not a Bosch part) can't remember the brand but it's a common one that you will get from either Centerline or IAP.
Anyway, the fit wasn't quite right and it ended up chewing up the inside of the cap. I actually took a picture of the original Bosch rotor and the aftermarket one side by side and could see that it was a couple of mm higher. I found out later that it does work but you really have to push to make sure it's seated all the way.
So take the cap off and look at the inside, maybe this is your problem. In my case the engine started but the distributor was making a gawd awful clattering noise.
Edit: I see from your post above that you've already checked that. Oh well, worth a try.
Paul - 1972 Spider - 1991 164S
Last edited by kcabpilot; 06-29-2012 at 10:21 PM.