problem in cancellation of entry sheet

Dear experts,

I am facing one problem in cancellation of entry sheet. IR has been cancelled for total amount. 0 value IR exists for same line item due to MRRL. while cancelling entry sheet thru Ml85 / ml81n getting error message saying PU IR deficit qty 0.001 AU. system wont allow to cancel that 0 value invoice.

Please help me to solve this.