Hi all, I am also facing the similar problem with xls format.
While exporting excel file am adding a HSSFDataValidation. Its a dropdownlist for one column in sheet1 and the values are generated in sheet2.
For example - States.xls contains country code column as dropdownlist in sheet1 and sheet2 contains the country code list . Till now its working fine.
If i do any modifications to the excel file and save it am getting a message "__Compatibility Report for sates.xls__".
The message says :- "__Significant loss of functionality__" - One or more cells in this workbook contain data validation rules which refer to values on other worksheets. These data validation rules will not be saved.
Can some one please help me how to overcome this issue.