As promised, direct from the CIC bulletins...
Domestic tickets (within Canada) issued on/after 01Mar, 2001 change fee will be CAD145. Tickets issued prior to 01Mar, 2001 will still be CAD100.
Transborder change fee increased for tickets issued on/after 31Jan, 2001. The new fee is USD100/CAD145. Tickets issued prior to 31Jan, 2001 will remain at USD75/CAD100.
As an aside, any ticket that was issued prior to the increase date and is subsequently entirely reissued after the increase, will be subject to the new levels.