On the David Element site it's called Epistrophe diaphana, the pattern is the same as mine, the colour may be slightly off but that might be the pic.
http://www.david.element.ukgateway.net/flies9hoverflies6.htm
On the French site it's called Syrphus vitripennis, and that looks spot on with both pattern and colour.
http://aramel.free.fr/INSECTES15terterter'-1.shtml
The French site has a female Epistrophe diaphana which looks very different.
There seems to be very little else to go on, the syrphidae.com website has the same pic as David Element's, and he has linked to it on his site.
http://aolsearch.aol.co.uk/aol/image?invocationType=topsearchbox.imagehome&query=Epistrophe+diaphana
There looks to be more on Syrphus vitripennis
http://aolsearch.aol.co.uk/aol/image?invocationType=topsearchbox.image&query=Syrphus+vitripennis
But when you read the minute differences between it and similar species, I'm lost!
http://www.entomology.ualberta.ca/searching_species_details.php?b=Diptera&c=7&s=5837
