Record of travelling

Hi everyone! I have one question about the stamp on passport when we come back to Canada:
I went to China for vacation for 3 weeks in 2009. When I came back, the boarder did not stamp on my passport. At that time, I did not think too much and just left. I checked my passport again, there is only one stamp showing I entered China, other than that, nothing. No record I left Canada and returned to Canada.
NOW my question is: when I renew my PR card, I need to show them the photocopy of each page of my passport to proof I have been living here for at least 2 yrs. If there is no record show that I came back, will they give me trouble? I don't know if I told the story clearly.
I am just confused about this situation. Thanks everyone.

Ditto.

You disclose, as part of your application, the dates of all travel abroad. You need to be accurate. Passport stamps and other CBSA records are not necessarily complete but they should be, at the least, consistent with your accurate reporting of the dates you traveled.

If there are questions, they can and oft times will request you to submit additional information or documentation -- a PR residency questionnaire. So, if necessary, you would have an opportunity to submit evidence and documents showing your presence in Canada, which should be relatively easy to do for anyone actually living in Canada.