Error in reversal entry

Hi all,
I want to Reverse one transaction.
But getting error message
You cannot reverse the transaction, because it has already been reversed.

I checked in table with fields Reversed, Reversed by Entry No & Reversed Entry No. from General Ledger Entries. They are blank. Means not yet Reversed. Still getting error message.

thanx in advance

Activate debugger and check where it is throwing an error .You will come to know where is exactly the issue

this error is also known in older nav versions.

maybe that helps