Yes you do! A friend of mine had to do it in June! Here's the link from CIC and the address!
The reason why people don't know about it, is because some get their PC from police stations in other cities and send them in. But if you go to the one listed on the CIC website they direct you to the consulate to have it validated. Better safe than sorry. You never know with Mexico, they might make you do it over. I guess it all comes down to the luck of the draw on which V/O you get.
http://www.cic.gc.ca/english/information/security/police-cert/central-south-amer/dominican-republic.asp
Procuraduría General de la República Dominicana (Web site available in Spanish only)
Centro de Atención al Ciudadano
Av. Máximo Gómez #21, Esq. Bolívar
Santo Domingo, Rep. Dom.
Telephone: 809-533-3522 (ext. 3028)
E-mail: info @ procuraduria.gov.do