I'm up in Canada and some of my cards are in French and some of them are in English. Is there any problem with using cards that are in different languages at the same event?

I would say no, otherwise international events would be impossible. Just be sure to have at least a copy in the currently offcial Language.

E.G. here in Italy we have card in German and Italian in the same box. Of course we use also the Germaan ones if we need more copis than we have in Italian. But we Always have the italian version available to be consulted by opponent

Well, considering FFG released some alt-art upgrade cards that are in aurebesh, I don't think anyone should be overly critical of cards in differing languages. As long as both players can read the cards or have examples in a language they can read, I don't see it as a problem.

Agreed.

Excellent! Thank you for your replies.