@McTag,
Vorsicht is right. Some time ago I had to go to a city in Poland formerly known as Breslau. I get to Berlin, go to Lufthansa transit desk, they send me over to LOT Polish Airlines, where I ask, politely, in German, for a boarding pass to Breslau. The lady at that desk practically screams right in my face:
"WRCLAW!" After that I was very careful to speak softly in French and pronounce the city's name in my best imitation of a Polish accent - good tip to remember, if you go!