Most cars I have had do this to different degrees. My current A5 does it sometimes when cold and slightly more if the car is moving. I find that gently rocking the lever into first works if it is being a bit stubborn.
I dont think its a fault though
What Speary said. I too reckon it is manual gearbox peculiarity inherent in many models irrespectively of the car make. When the thing warms up it's gone. You might want to check another thread pertinent to the issue, titled "1st gear question".
Enjoy the car and don't let it monopolize your thoughts. After all, who needs 1st gear with all this torque available.
In the past when it gets really cold, I've had the experience that both gear box and power steering were stiff in my previous cars. Probably due to the fluids in the gear box and steering system being cold and dense. (Molasses in January?) This always went away very shortly after I started driving. So, the message, as other said, is that you need not worry about it unless other symptoms occur or the problem persists after driving.
''Simfono apolita'' I totally agree as we say in Greece with Geo...I had the same problem during the first 2000 km, even when the car was warm...Now the problem reduced and the first gear is more easy to put in..After 2000 km, I still have the shifting problem, only sometimes, when the car is cold...
Try to enjoy your A5...As you drive it more and more...it learns from you and you learn from it....