A loggbackup file is not copied from $bkp in the Vista database to the place specified in the backup object.
SQL 2005 express
When the SQL server is finished with the backup it tells Vista, and Vista then copies the bkp file from $bkp in the Vista database to the place specified in the backup object in Vista.
In this case the SQL server succeeds with the backup but fails to put it in the history log called dbo.backupfile in the MSDB database. So Vista never gets the message that SQL is finished and doesn't move it to the right location.
The dbo.backupfile table in the msdb database was corrupt and needed repair.
Contact PSS or have a SQL expert check the msdb database.