Correct me if I am wrong, but from what I recall D&O Insurance is related to the date or dates on which a covered event occurred. So if D&O insurance was in effect during, say, 2008 then anything that happened in 2008 would be covered.

If it has been in continuous effect from, say, 2006 up until now then any triggering event(s) since 2006 would be covered. Assuming the premiums were paid.