Logical recovery failiure

Hello, I hope this is the right place to ask this kind of questions. I'm taking care of installation of an application, that uses Informix DB server, version 7.3 and I have this problem: every 2 weeks or so DB server stops for no obvious reason and in logs are this errors: IEEC events: 1) Logical recovery failiure, restore operation failed while recovering database transactions from the logical log ( repeated 3 times ) 2) An internal subsystem failiure alert occured 'MT' ( repeated 2 times ) Logical log backup is made to the disk. conol_DBserverName.log: Assert failed: Rollback error 101 Who: .... thread(.... sqlexec ..... ) Result: Log record .... was not rolled back At the time this error occurs, application doesn't do anything extraordinary. It does only things, that it does all the time, that is, it fills the database with records that come from the network of electronic door locks. After I restart the database, everything works fine. Does anybody know, what might be the problem ? Regards, Mitja Zabukovec