Line Type default purchasing category

All:

I have defined a new quanitity line type e.g. Computer with a defaulting purchasing category of Computer, and UOM of Each.  When I created a Requisition or a Purchase Order with this Computer line type, category and UOM did not get default from the line type, these fields remain blank.

I expect the category and UOM to default from the Line Type setup.  Am I wrong in my expectation?  Or did I miss some setup?

Please advice.

Thanks