Looks like your months are screwed up as we currently stand on 27 OCT 2010. Let me give you a generic answer. While you are living in Canada in PR, leaving the country temporarily does not impact on your status. You must be present at least two years ( or may be three) out of five consecutive years to maintain your PR in Canada. After living in Canada for 3 years (accumulated basis - not consecutive), you can file for Citizenship.

I don't see how you will be able to maintain your US GC while living in Canada though. If you are away from the country without valid reason (eg., working for US company outside of US etc.) for more than one year, then you automatically lose US GC.... Hope this answers your question.