This is the Official 'Workaround' for this problem. As already stated in an earlier answer by
RobG 
TIS 2000 Service Information
Field Remedy 1417
Subject: Electronic Air Conditioning
ECC-Window fogging after engine start.
Complaint: The windscreen will suddenly start to become fogged inside due to increasing humidity inside the car.
Cause: At outside temperatures of -5degC and less with a battery which is not fully charged, recirculating flap is switching to recirculation mode if the supply voltage drops below 9v for a short time.
Production: As of VIN W0L0VBF6921013332 a corrective action has been introduced in production.
Remedy:In case of Customer complaints see the above Instruction. This failure can be identified when the problem disappears after switching on and off the recirculation function.
Procedure: First switch on Auto mode, switch on the air recirculation by pressing the
'A' button once (3 round arrows will be indicated without the letter "A" in the middle) Now the EEC will recognise the correct flap position. Wait 1-2 seconds & then switch off the air recirculation by pressing the "A" button once again.