There could be any number of reasons, it depends on your circumstances and without more information about you, it is useless for us to try to speculate. It took us 81 days as we needed some paperwork from the province of Ontario, and another poster, British_Bulldog, surpassed us with some 90-odd days required for her approval, and I believe it was because it took that long to confirm that she had fulfilled the PR residency requirement (if memory serves me right).
So, in other words, think about yourself and your circumstances and what may be causing the delay in your being approved to sponsor.
Thanks for your reply. I know each case is different. I am trying to figure out myself why it is taking too long. I called the call center and they didn't say me any reason. I thought they are taking time to verify my non accompanying spouse information. But now I am confused because it should not take them such a long time to find the information.
By the way how do you know the cause of your delay? What do you mean by PR residency requirement? Could you please explain it? I got PR in May 2009. I return in Canada Sept 2011. As per I know in order to maintain PR I have to stay 730 days out of five years. So I thinnk I am ok.