Excel 2007 Pivot Table Changes the Source Data Range
 

I have several Excel 2007 files with Pivot tables in the files. When the
files were created the source range for the data was (nameofsheet $A:$J) and
now all the files have changed the data source in the Pivot Tables to the
following: (name of sheet $a:1:$J$16384)

As it turns out 16384 is the maximum number of columns allowed in a pivot
table, but, Im not sure why all my files are changing to that.

Has anyone come across this?