http://www.cic.gc.ca/english/resources/manuals/cp/cp05-eng.pdf - page 16 and 17 said:
Indications declared residence may be in question
The following list, while not exhaustive, includes indications that further inquiry into declared
residence may be required. It is important to note that indications alone do not necessarily mean
a case of residence not being met. Their weight and credibility vary and must be considered in
conjunction with all information on file.
...
— Passport
• Stamps in passport indicate that the applicant has not declared all absences from Canada.
• When coming to write an exam or to have a quality assurance interview, the client’s passport
shows recent entry stamp to Canada or an exit stamp from another country.
• Client presents a new passport but cannot account for passports used during the relevant
four year period, or client is in possession of a new passport issued outside Canada.
• Client is asked to present passport at an exam or scheduled appointment but does not bring
it.