Administrator account keeps getting disabled in SAP BI 4 from time to time.

Hi,

I am working for Ericsson. Recently during a upgrade for a customer, we migrated from SAP BO XI 3 to BI 4 Platform. Everything is running fine, but the Administrator account keeps getting disabled from time to time. They need to login from any other account with Administrator rights to enable the Administrator account to resume operations. What can be done for this problem?