Problem with with tlds.

Hello I was thinking if anyone could be of much help. I have a site, Toronto Lofts, and I have registered both the .com and .ca domains for this same site: urbanopoli.ca and urbanopolis.com. It is a real estate site and we sell lofts and condos in Toronto. I am using a redirect from the .ca to the .com. However, I was wondering if there is any potential harm from this action. Is there any chance that the search engines will see them as duplicate sites, and maybe penalize one of them?
Check my main site here: Lofts Toronto