Message 13228 in the database log when shutting down prevents shutdown

Message 13228 in the database log when shutting down prevents shutdown.
Total of remaining buffers in message 13228 never decreases.
No PROSHUT commands will shut down database.

An issue with the buffer pool's dirty buffer count prevents shutdown from completing.

Upgrade to OpenEdge 10.2B or later, where shutdown improvements in OpenEdge 10.2B and later also introduced the -shutdownTimeout parameter to limit the time period the PROSHUT process will wait for the database activity to end, before immediately shutting down (killing users still connected). If all normal activity ceases before the timeout value is reached, normal shutdown proceeds. If not specified, the default is 10 minutes.

First try an emergency shutdown from a seperate session: PROSHUT db -byF.  
The process would not be allowed to continue to run while the database was in shutdown mode.  The processes would only be given a little while to continue to work until kills would be issued against all processes which would occur much sooner than a conditional shutdown.  Otherwise more drastic measures such as killing PIDs, removing shared memory segments etc are needed.

If the reason for shutdown is to take a backup, consider online backup options which would minimise the number of times proshut may hang on flushing the buffer pool.

References to Other Documentation:
Progress Article(s):
Is there a parameter for PROSHUT that will allow a DBA to control how long it takes to shut a database down normally?