I found strange too. Anyway, i ll ask employer to provide letter in this regard. even i never changed employer.
un_jour_de_reve said:paystubs may work too. This is a really strange case, it is really first time I saw and heard someone need to provide all expired health card. Never before.
I heard before the problem of Saskatchewan health card do not show birth date and only show birth month and CIC require "identification should show your name and date of birth". The CIC agent that I called said ID must show date of birth, month is not good enough, then I had to provided and Copy of another Government ID.