Hey Naz, Laura and Mamm,
I am in the same situation as you guys!! I sponsored my husband in October 2011, and on August 29th 2012 our file was transferred to the local office for further assessment...and since then we've heard nothing. I've been trying to find people in the same situation as us for such a long time now. We've never been asked for any additional proofs of our relationship, or for any other documents. Apparently they transfer your file if they have doubts about your relationship, or if they want something extra from you.
We did our application through a consultant and we thought we included enough proof....we're a young couple but we've been married for 2 years now. Guess it wasn't enough!!! I've read about people who have had their file transferred, send in all the proofs they can find to the local office, and have their interview waived. We're getting everything ready to do this, but the only problem is that the Montreal office hasn't even confirmed that they've received our file ??? !! I wish CIC had asked us to send more proof, we have so much! I even took screen shots of all our facebook chats for the last 3 years.
Our consultant told us about some of her other clients. One guy had his file transferred and waited over a year for AIP, just because he didn't include a police certificate...why they couldn't have just asked him to send it in the first place, I have no idea. I think it's likely that we'll have an interview, which would be so much better than waiting for months and months.
What's even more frustrating is that since we live in Quebec, my husband and I have been approved already through a CSQ....so Quebec is fine with us, but Canada is making us wait...we thought we already had AIP up until about a month ago.
Anyways, just wanted to share our story...we should keep each other updated!