The Society for the study of flies (Diptera)

I, for one, am comfortable with you posting stuff like this here. These Recording Scheme Forums need to be used.
You've drawn it to the attention of a group of people who might perhaps have more Diptera expertise than the general flickr people.
I don't wish to draw attention away from this Dipterists Forum site but you may find even more success in getting an identification by linking this topic into the www.diptera.info site and posing your question there as well. Paul Beuk, who runs that European site, has a habit of hunting down ID topics such as yours and providing a decent identification on the originating site. I've seen quite a few US sites that start with a picture and a question, elicit a few useless "wow"s and "gee"s then end with a Paul Beuk ID.
Do it as a link to this DF topic, though, as it may attract a little more usage from diptera.info people to this Dipterists Forum site.
Good luck