Here is a little hint: if your item has construction requirements other than "Craft Wondrous Item" then it is getting rejected because it ISN'T A WONDROUS ITEM. So if you are contemplating submitting an item that requires Craft Arms and Armor or Craft Rod or whatever, then you might want to think again, since the rules of the round clearly require a Wondrous Item.
So, in the interests of keeping it positive and not focusing on what NOT to do, here we go: Make sure your item requires Craft Wondrous Item as a construction requirement. If it doesn't then maybe you aren't actually submitting a wondrous item.
Also note, the Feat is called Craft Wondrous Item - not Craft Wonderous Item.
A clarification on what Clark said above; your item isn't getting rejected for using a different crafting feat, it's getting disqualified.
Your item isn't even being looked at, or considered for it's merits. Disqualification means your item didn't follow the competition rules, which is the most basic of tests of your potential. Like not writing your name on a test at school, and getting a grade of 0 as if you missed it.