Dear jojobaba,
I was born in India but have lived 99% of my life in nigeria. I am giving you an information that no one ever gave me, that's why am in this situation that I am. To be candid with you, I didn't know the implication of the circumstance until I got the letter that accompanied my visa. Ok, I will explain myself again:
***********Application submitted in august 2005. I was single at that time, but was in a boyfriend-girlfriend relationship with the person am now married to. She was still doing her undergraduate in nigeria while I was doing my Masters.
***********July 2008, medicals done
***********December 2008, I flew to nigeria to marry my wife. Unfortunately, no-one was there for me to give me to guide me/inform me that I needed to inform the CHC or I would say it completely escaped my mind.
***********Early January, 2009, received a letter to submit my passport but in that letter CHC never mentioned me to inform them if there is a change in my marital status.
************Mid february 2009, received my passport with visa and COPR and an accompanying letter saying I can't go and land in canada if there is a change in my status and also that I will never be able to sponsor my wife in the future. I was so shocked that I could not sleep for like 3days. I e-mailed CHC regarding my wedding, they asked me submit my wife's processing fee, police clearance, birth certificate, 4passport photos, and to fill out some forms. I was also advised to return my passport with visa and COPR for cancellation. This really disturbed me I can't lie to you. The reason is because I have sold my car, cancelled my house rent, left my job, told all my friends/families that am emigrating. I don't pray anyone else falls into this kind of a situation. It is the most difficult period of my life. I will tell you why:
I returnned my passport with visa and COPR with other requested documents in february ending, CHC sent a medical form for my spouse in April 2009, my wife did her medicals in nigeria and we was received bt CHC in london around early May 2009.
************Then in late June 2009, CHC sent my passport back (so I was unemployed from february till today as no one was willing to give me job without my passport).They have cancelled the visa( It reads 'CANCELLED WITHOUT PREJUDICE). They now requested me to re-submit my passport and that of my wife together. I have sent the two passports off. By next week it will be 6weeks which is the deadline the CHC says they will be returning them with visa.
Now to your answer, the reason the CHC would cancel the visa is because they will do medical and security assessment for your wife too. She must pass all these. If she fails, they will cancel your visa and will not re-issue you a new one. Also if she is a security-risk, they will cancel your visa and will not re-issue you with a new one. If you inform the CHC, you just wait for their instruction, if you go and land after informing them, they will report you, you will be removed from canada for misrepresentaion. If you don't inform them, they will do a background check when you want to sponsor your wife, they will find out the exact date that you were married. This information am giving is very important. I wished someone had given me such information immediately after my wedding.
Finally, if you marry immediately after you receive your PR, CHC will also need a proof that you were not in a common law relationship prior to your wedding. I have read in this forum of a similar case. My best advise is to always tell the CHC the whole truth, nothing but 100% truth. At the end of the day, one's conscience will be clear if you have told the truth. Somebody said I should go and land without informing CHC that I am married I don't know how I would have survived with such high level of dishonesty. That person is still pitying me now because he is still seeing me around when I should have travelled since february. The end of my story is that the truth shall always prevail because next week when I receive my visa and that of my wife with COPR, I will let the person know.
I hope this information is more than enough, if there is anything else you need to know, feel free to let me know. Experience is the best teacher at the end of the day.