I dont have personal experiences neither do I know anyone personally anyone in this situation but, I do remember reading on this forum about a person who waited 7 years to get citizenship because his passport was renewed from his home country. CIC just did not buy into his story that he renewed it when while vacationing there. According to him his file got pushed to the bottom and the whole process took 7 years.
In reply to a post that its non of their concern. I agree, it shouldn't, but the fact of the matter is they are concerned with everything. From your travel to your passport. Even if they are gaps between your expired passport and new passport they raise an eyebrow.