Locked Tax Code Posing in Incoming Excise Invoice

Hi Experts

I have locked a TAX CODE for which i have posted a GRN before Locking,When i post Incoming Excise Invoice for that

GRN After locking the TAX CODE, SAP is allowing me to post the Incoming Excise Invoice.and its not allowing to post AP Invoice,How can i restrict a locked TAX CODE in Excise Invoice too. Please give a solution for this issue...

reagards

Naresh.K