Just did a reinstall with the version I have (1.0.1, downloaded June 8) and added the Canadian pack. The Language for Français CA(French) is iso =>qc , language code => qc. Setting the local (language code) to fr or or fr-ca fixes the issue. I guess the Canadian pack should be configure iso=>qc, local=>fr-ca
The page in question is is when a /fr/connexion when a user creates an account during the checkout process .
As a side note, users should really add the French language pack (Localisation / translation ) after the Canadian pack because to get the base theme working (you get missing email notification template and such ) .
I must say ThirstyBees is quite complete so far, and I can fix any issue by moving around in the code. Great job