Engine Misfire Codes

I am having an isolated engine misfire issue with a 2002 911 Turbo with the X50 package. 

Only when the car is started from sitting overnight and allowed to idle until warmed up I will get the following misfire codes: P300, P303, P306. 

If after starting the car I rev the engine to 2 - 3K rpm's three times and each time releasing it immediately and then I let the car continue idling to warm up the check engine light will not come on.  Or if I drive off right away it will be fine as well. 

As stated above this problem only occurs if the car has not been used overnight.  If I drive the car to work and start it a few hours later there is no problem.   Thanks for any help.