Interesting. They didn't seem to car when I exchanged my Australian license. Though I was pretty close to the six months at the time.
But, another classic example of how English rules don't work. You can't get a residents permit for parking your car in London unless you have a UK drivers license with your current London address on it. But if you are new to the country, you can't get a UK drivers license for six months.
Thanks for another reminder about why I love Switzerland so much.