Is it possible to change the Depreciation Expense Segment in the Asset Categories Form?

 Hi-

We've established additional depreciation expense accounts, and I need to update the dprn exp coding for some of the Asset Categories (11i).  When I try to change that field on the Asset Categories Form  I get a message that the "Field is Protected Against Update".  Is there a way to change this value?  ...I'm trying to avoid having to establish new Asset Categories.

Thank you-