Thanks, what does "dormant" mean in this context though? Can the account be re-activated, ie miles added to or does it get locked and nothing more can be credited?
Have you bothered to check at Aeroplan.com?
Question:
How can I make sure my Aeroplan miles do not expire?
Answer:
When you stay active in Aeroplan, you make sure that your Aeroplan Miles don’t expire. All it takes is one transaction every 12 months to keep your account active
http://www.aeroplan.com/help/topic.do?id=1004
Expired as is dead, passed away, gone, closed and miles forfeited back to the airline, though they make you an offer to sell them back to you if you inquire as to why your miles are deceased.