I agree with the last 2posts, ride sensibly and you should be ok.
I think the most likely place you will get troubled by the French Police is on the motorway racing back to catch your ferry near Calais, it seems to me they like catching English drivers on this last stretch!
New French Traffic Laws
As from 1st July 2012 it will be compulsory for drivers of all motor vehicles including motorcyclists, excluding mopeds, to carry a breathalyser in their vehicle while travelling in France. This will not be enforced until the 1st November 2012, where persons failing to produce a breathalyser will receive a fine on the spot of 11 Euros. The breathalyser has to be certified by the French authorities, showing an “NF” number. It is recommended that two single use breathalysers are carried, so if one is used or damaged you will still have a replacement to produce.
(Breathalysers can be obtained on board Ferries I believe.)
Effective from 1st January 2013, all drivers and passengers of a motorcycle over 125cc or a motor tricycle over 15kw/h must wear reflective clothing when riding their vehicles. In the event of an emergency stop, the reflective clothing still needs to be worn.
The reflective clothing must have a minimum reflective surface of 150sq cm (approx 23 sq inch) in total either in one piece or in several pieces, and must be worn in the upper part of the body (between the neck and the waist). A fine will be imposed for non compliance.
It is absolutely prohibited to carry, or use radar detectors.. Failure to comply with this regulation involves a fine of up to 1500 Euros and the vehicle and/or device may be confiscated.
As part of the changes to French motoring law, road signs indicating the location of fixed speed cameras are being removed and traditional fixed speed cameras added. A GPS based navigation system which has maps indicating the location of fixed speed cameras must have the “fixed speed camera Points of Interest” function deactivated, ideally they should be removed.