Although I wouldn't say this is official, the online SRD rules both state the DC is 5 + caster level of item.
http://paizo.com/pathfinderRPG/prd/feats.html (Skill Check, First Sentence)
http://paizo.com/pathfinderRPG/prd/magicItems/magicItemCreation.html (First paragraph, Fourth Sentence)
I feel 5 is too low, myself, though it would be fine if they rewrote it so you created a cursed item if you succeeded by 5 or less. Just my opinion though.
