Thought I would post the following response from AP to a missing flight credit request...
Air Canada and the Star Alliance partner airlines have recently adopted a new missing flight credit validation process.
We have been advised that several components of the process have not performed as expected with the result that many entries have been rejected. One of the missing flight credit entries rejected is unfortunately yours. Rest assured that Air Canada’s Information Technology Team is working on a permanent fix however we have not been given a specific time frame as to when to expect your flight miles to appear in your Aeroplan account. We will monitor the situation and communicate any new development.
I guess the crux of the message is, if your flights haven't posted after 6 weeks...wait another six weeks. But, don't despair as ACs IT team is "working" on it!