TYPO3 Core

We have extended the fe_users table and mapped it the following way

config.tx_extbase {
    persistence {
        classes {
            Tx_PtEubBase_Domain_Model_FrontendUser {
                mapping {
                    tableName = fe_users
                    recordType = Tx_Extbase_Domain_Model_FrontendUser
                }
            }

            Tx_Extbase_Domain_Model_FrontendUser {
                mapping {
                   tableName = fe_users
                   columns {
                       lockToDomain.mapOnProperty = lockToDomain
                   }
                }
            }
        }
    }
}

We get on our Production System the error that table "Tx_Extbase_Domain_Model_FrontendUser" does not extist. This happens randomly. Cleaning cache with Install tool helps. We are monitoring the system and can see that when it happens System is working correct again some time later.

We can't produce the error on the Testsystem.

We are using TYPO3 Version 6.2.26. The same code worked with no problem on TYPO3 4.5