Sales Price Level Conversion


I have run the Sales Price Level Conversion Program (P41816)
I have updated to price level '1' from a default Branch Plant. The program has changed the "Sales Price Level" field of the Item Master (F4101) from a 2 to a 1. So far so good. Now I am trying to maintain the base price for the item in base price revision (F4106) and I,m getting an error message display "0026 Not Authorized to this Record" I can't maintain the price at either the item or branch plant level and I can't change the price level back to 2. I have access to the Item Master and Branch Plant Master file.
Has anyone else experienced this? Is it a security issue?

Paula Crepeau