Gulbrand Trulssen b. 1774.02.24 Modum. Which wife?

i was hoping someone might be able to give me some direction of have some information for me. my ancestor, truls gulbrandsen, b. 1801.06.15 in lier, buskerud has parents listed in the ministerialbok as gulbrand trulssen & mari olsdatter. i have traced gulbrand trulssen quite far back, but i have found nothing on mari olsdatter. when i search digitalarkivets 1801 census for gulbrand trulssen, i find one listed with a wife mari nilsdatter. gulbrands age seems to work as does the area: http://digitalarkivet.uib.no/cgi-win/webcens.exe?slag=visbase&sidenr=29&filnamn=f18010626&gardpostnr=21&personpostnr=668#nedre i cannot find any marriage info for a gulbrand trulssen/mari olsdatter, but only for a gulbrand trulssen/mari nilsdatter: http://search.labs.familysearch.org/recordsearch/start.html#p=recordResults&searchType=close&toYear=1801&placeId=1927171&alivePlaceLoc1=Norway&year=1774&surname=trulssen&givenName=gulbrand i guess my question would be- is it likely that the ministerialbok for the birth of truls gulbrandsen listed the name of his mother incorrectly? or am i missing something, and this trulssen/nilsdatter combination is not the correct one i am looking for?