Today I encountered the situation that after having changed the BIPLATFORM password in de 11g database and in WLS Enterprise Manager, the account locks every x seconds.
To make a long story short: the bipublisher jdbc connection and the RTD jdbc connection also use the BIPLATFORM schema.
So you need to reconfigure those as well.
Oracle Database 11g uses user-profiles. One of the options is password expiration.
So make note that if you hit such a situation, don't overlook the jdbc connections !