Unfortunately, there's not a single analog trunk on the MCD. This would have been a test, and likely the workaround for these numbers.
BUT... BUT.. I'm in Dusseldorf now changing the Nortel Option 11 with a Mitel MCD, and I've got the exact same problem.
Those numbers worked on the Option 11, but not on the MCD. No analog trunks here either. So yeah, since we made the change, the Telco says it's our problem (obviously).
Any ideas?