Customizing error in work schedule rule

Dear Guru

We have created new work schedule rule w.e.f.1st April-2013. following is the details

                                                       New                   Before

Employee subgroup grouping          2                     2
Holiday calendar                              S1                   G1
Personnel subarea grouping            01                   01
Work schedule rule                           DPUN             PAH2

and generated the work schedule rule from 042013 to 122013 and assigned newly created rule in feature "SCHKZ" are as under

Feature :- SCHKZ

A Active employee

|-   BTRTL Personnel Subarea

                  |- 1001

                          |-DPUN

           |-

                 otherwise

                   |- PAH2

Also assigned newly created calendar S1 to personal area. and assigned new work schedule rule DPUN to employee in IT7 w.e.f.01-04-2013 to 31-03-9999 before that other work schedule was assigned to the employee.

While executing the payroll for the month of April 2013 system are given error for previous work schedule 

"Customizing error in work schedule rule 2 S1 01 PAH2

If we hiring new employee and assigned new work schedule rule then system are generated payroll result.

So  pl help where we have  done mistake in customization.

Please suggest the same as it is very urgent as we have to change the work schedule rule to all the employee and run payroll for the month April-13.

Regards

Vijay