Hi Raja,
Report /SAPAPO/CHECK_LOC basically helps to identify any discrepancy between the tables /SAPAPO/LOC and /SAPAPO/LOCMAP.
Please check the report for your location and see if the report throws up any discrepancy - Also there are reorganization options available within the report. Also there is another report - /SAPAPO/CHANGE_LOGSYS - Please check this too.
Also please check this Wiki Link on Locations and other useful reports/tables present -
Location - Supply Chain Management (SCM) - SCN Wiki
Hope its useful to you.
Regards,
Alok