if you was army man or your work had some relation with security or secrecy, maybe you would have some trouble. the Immigration officials will send a request to the Canadian Security Intelligence Service(CSIS) and ask CISIS to make an investation about your background. If that,just like me ,it is very unfortunate. the background will cost half a year or one year untill two year because there are too many persons will be checked and hard to make this investation. So , When you fill in the application table, be careful ,DO not say you and your spouse worked in the army etc.
good luck to everyone.