Authorization Error while creating PO and A/R Credit Memo

Hi Experts,

We use SAP B1 2007A, PL:08. Some of the users are getting this error message while adding the PO, A/R credit Memo etc. As a superuser, I am able to perform this action.

The Error Message is "[A/R Credit Memo-Rows-Discount % per row] [line:1], you are not permitted to perform this action'[message 200-30]

Any idea why this is happening. I checked the authorization for the users. They have full access to Purchasing and Sales modules. Am I missing something here? Please let me know!!

Thanks,