http://archives.tdg.ch/geneve/actu/accord-franco-suisse-fait-pleuvoir-amendes-2010-03-31 I don't know whether this helps. It's from 2010 so it is two years old... 

I received several fines eighteen months after the incidents then there was a gap of 6 months and i got another few

I too live in France 

I am more careful now

That article is interesting (if I read it right ) as countries did not share information until January 2010 - and yet all my offences were from 2008 / 2009   - I wish I had seen this, I would have appealed !  

Consider buying a small 20€ GPS unit in Carrefour, which keeps track of the stated speed limit on the road, you are on - and beeps, when you exceed the limit. They are legal and useful, whereas, (no comments), radar databases are not anymore.

Are these night time fines or daytime fines? I find that not driving through Geneva when tired is the best way not to pick up fines. 

For me they were daytime all drving to work or back. The first batch were all in a two week period in a hire car i was not familair with during the fist few weeks of moving here  - and all on the same stretch of road cos I didnt realise the speed limit

I paid them all it came to thousands 

Hi Guys

Thanks for the info, I was speeding during the day taking clients to the airport, so I take it from the above it does not matter how long ago they where they have to be paid.

Paolo