Engine fires then dies immediately

[tranceatlantic]

Follow up:

The same problem has happened intermittently over the last year. I'd say about 5 times in total. The engine seems to fire but dies immediately. Maybe its not even firing, I'm not sure. But it sounds normal until you get to the point where you would normally let go of the key. It seems more likely to happen if I give the engine a false-start, like when you turn the key and it slips in your hand so it doesn't have enough turn to get up and going. Its not a big problem - I just always need to have a 10mm socket handy to pull the battery connection, then everything is fine.

I was just wondering if anyone has seen this problem? Is it really a case of my DME crashing and needing a reboot? The first rule of IT is 'have you tried turning it off and then on again?'. Is this going to be the first rule of Porsche's?