"Incorrect period" error while executing J1INQEFILE

Hi

I am running J1INQEFILE. I gave company code as 1000.

Fiscal year 2011.

Period: 09 (as december is 9th month of FY 2011)

Fiscal Period: 01.12.2011 to 31.12.2011

Clearing Date: 01.12.2011 to 31.12.2011

When i press enter, it gives error: Incorrect Period and cursor moves to Fiscal Period.

Please tell me what is the error. I am trying for invoices that are posted in december 2011.

Please help