What if you no longer have your old passport?
My original passport, which would have expired in 2010, sustained significant water damage (to the point of being unusable) and I had it replaced last year (March 2006).
The damaged passport was returned to me with the new replacement, but I destroyed it thinking I was being diligent. It seems I was actually being careless!

Has anyone gone through a similar experience? Did you explain the absence of your previous passport? It doesn't seem that uncommon that someone might have lost their old passport and therefore can't send it - so I'm wondering what I should do to explain this in my EC application.
Thanks for any advice!
Amy