Yes, all three boxes relate to one dividend. Box 23 is the actual amount you received, box 32 is the grossed up amount (it is meant to represent the amount before the corporate taxes of the issuer of the dividend) and box 39 is the dividend tax credit.
http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/rprtng-ncm/lns101-170/120/menu-eng.html
http://www.cra-arc.gc.ca/tx/ndvdls/tpcs/ncm-tx/rtrn/cmpltng/ddctns/lns409-485/425-eng.html
