EuroATC, I am sure it has nothing to do with frequencies. Here there are so many different nationalities in a relatively small amount of airspace (compared to Canada) speaking in a second language, that misunderstandings are bound to occur.
I regularly fly through Geneva ATC,and even though I am British still find various accents confusing, so God only knows how the Pilots whose first language is not English manage!!
Haven't heard a Canadian accent yet, though!
Regards all,