login and syncronize in navison 4.0 SP1

Hi all We are using Nav 4.0 SP1 at one of our client location. Client is using database logins. Whenever user try to login most of the time it throws following error: --------------------------- Microsoft Business Solutions-Navision --------------------------- The following SQL Server error(s) occurred: 2764,“42000”,[Microsoft][ODBC SQL Server Driver][SQL Server]Incorrect password supplied for application role ‘$ndo$ar$87653EC34B163A0CF14FC9A9763F08C2’. --------------------------- OK --------------------------- It is coming for most of users. Even for user with super roles also. IT is very frustrating for client and us. IS there any solution for this error. Please reply ASAP. What can be the possible reasons behind it? Anticipating a quick reply Regards Param