Do you have different exclude lists specified for the client? If you have a more specific exclude list for the client, it will use that one instead of a general one you would have created. For example, let's say you have a client A. Now you have two exclude lists for that client:
1. First exclude list excludes file c:\temp on all policies and all schedules.
2. Second exclude list excludes file c:\test on just policy B and on all of its schedules
When you do a backup of policy B, it will use the second exclude list instead of the first exclude list. So c:\temp would still be backed up since it would use the second exclude list instead.