Denda,
I had issues earlier with our BE DB instance - In our case, I had installed BE when MS SQL2005 was still at SP2 (currently SP3). Via Windows update, SP3 kept failing to install - the reason being that I did not use BE's normal embedded SQL 2005 Express Edition install and had set up its instance on the MSSQL 2005 standard install we already had (Symantec advised that using EE was preferable, and using any other version of MSSQL 2005 could cause issues). Removing the instance and setting up BE's EE instance proved successful to clear this up. Have been running on SP3 for close to a year now with 12.5.