If the service that had a common session ID was started by the scheduler, than Yes - the problem has been fixed in 6.0.1 and there is a fix available for at least one of the 4.x releases.
The problem was multiple threads where using the same session, therefore, the same session ID. This is the core scenario that caused the problem.
HTH,
Fred
#webMethods#Integration-Server-and-ESB#Flow-and-Java-services