Error In Quotation - ASAP

Dear All,

Our all item are excisable. When user select this item in quotation and try to post it we get the following error:

There are Excisable Item(s) with non-CENVAT tax code [Message 140080010-13].

In quotation client will never select the CENVAT code. How to solve this problem.

Any solution will be highly appreciable.

swapnil