What could cause a pivot table Column Label filter to not be maintained?

I've created an SMI report with a pivot table in the spreadsheet, and set a field called YEAR to be a Column Label in the pivot table.  The values in YEAR are 2011, 2012, and B2012.  The column is formatted as Text in the raw data.  I am setting a filter on the field to display only 2012 and B2012 data.  I then save the template, link it, close it, and rerun the SMI report.  The issue I'm seeing is that when the report runs, the filter has changed so that only 2012 data is shown.  I have to manually change the filter if I want to see B2012 data along with the 2012 data.  This is a problem because I need to generate a calculated field using both 2012 and B2012 data.  If I set the filter to show all three values, i.e., 2011, 2012, and B2012, then the filter holds when the report is rerun.  But setting the filter to show only 2012 and B2012 causes the filter to inexplicably change to show only 2012 data.  Any thoughts on why my pivot table Column Label filter setting is not being maintained?

Thanks.

Sage 500 ERP v7.30.5, SMI v1.00.0073, SQL 2008 R2, Excel 2007 SP2