Lost in translation

I've spent this week working on the copyedited version of Silent Saturday, going through the copyeditor's comments and agreeing (or disagreeing) with proposed changes. Most of the suggested amendments are minor and pretty uncontroversial, but there are some special challenges in setting a book in a foreign country, as I have done.
My first three books were all set in the Eifel region of Germany, and although they were written in English and the dialogue was in English (with the occasional German word or phrase for a bit of colour), it was understood that the dialogue was an English rendering of conversations that would in reality have been in German. I had to take great care, therefore, that I didn't use any English phrases for which there is no suitable German equivalent. I could say, for example, that Klara Klein had "bitten the dust" because in German someone can "bite the grass" (ins Gras beißen), but I would not have Steffi Nett say that she would "give someone the top brick off the chimney" (ie. do anything for that person) because a German would not say that. Whilst I was writing those books, I constantly kept the theoretical German text in my mind.
My new Forbidden Spaces trilogy (coming in April 2013) is set in Belgium, and this presents different problems. Veerle De Keyser, the heroine, is Flemish-speaking but she lives in a village close to the cultural and linguistic faultline that divides the Flemish- from the French-speaking population. Most of the characters who appear in the trilogy are Flemish, but a number are French-speaking.
Towns and cities in Belgium often have a Flemish name and a French one, and sometimes even an English one too. Thus what we Brits call Brussels is called Brussel (Flemish) and Bruxelles (French). Antwerp (English) is Antwerpen (Flemish) and Anvers (French). Ghent (English) is Gent (Flemish) and Gand (French). So which versions to use?
An obvious solution is to use the name used by the local residents - Antwerpen, Namur, etc. However, some parts of suburban Brussels have both Flemish- and French-speaking populations (eg. Auderghem/Oudergem) so it is hard to know which to choose.
I then wondered whether to simplify matters by anglicising all the place names. This would also forestall anyone unfamiliar with the Flemish version of Brussels, Brussel, thinking that the missing s was a typo! Aha, I thought, a great solution....until I realised that the "English" version of Brugge, "Bruges" is actually also the French version. A Flemish-speaking resident of this city in north Flanders wouldn't think of it as Bruges. Veerle certainly wouldn't.  In the end I concluded that there is no "one size fits all" solution. Where a town is firmly Flemish-speaking, let it have a Flemish name; where it is French-speaking, a French one. Where it could go either way, I shall use the Flemish one since that is the one Veerle would naturally use. I shall use the English name for Brussels, hoping to avoid enquiries about the "missing" s and keeping things safely neutral in this political and linguistic minefield. Inconsistent, perhaps, but it strikes me as a nicely Belgian compromise. 

                                                            Ghent, Gent or Gand..?