backup Db2- unable to force applications

When trying to backup a db on db2 LUW 9.5, I get the following message, even after running quiesce.

SQL1035N The database is currently in use. SQLSTATE=57019
 
There is some good advice involving authority here: http://www.dbforums.com/db2/1663529-backup-db2-unable-force-applications.html#post6596923

However, it did not apply to my situation.

In desperation, I decided to just restart the instance.
When I did, I got an error indicating invalid credentials.

I had to go into the Windows Service and change the password for the user.
That cleared up the issue.

Whaddya know...