Problem in Re-Hire of an employee with Old Personnel ID

Hi,

   I tried to Hire an employee on 01.01.2013 and terminated the same employee on 10.01.2013. Now I tried to Re-Hire the same employee with old personnel number on 20.01.2013. It throws messages as

1. Person already hired (Warning Message).

2. Employee Active Since 10.01.2013(Error Message).

Thanks

Avi