Using POI HSSF I created huge excel file with 26600 rows and 20 columns and when I open that file using Excel 97 or Excel XP it crashes. The generated Excel file size is around 10MB. Basic information about data: Most of columns are Strings and some Columns or Double with cell style set to using dataStyleSum.setDataFormat((short)38); Some columns have value null. Itried in 2.0-prev3, 2.0FINAL, 1.5.1 versions and in all versins it failed.
Please try with a later version, and if it still doesnt work, please try and isolate the bug and provide detailed replication method. It is wrong to assume that all 10MB files created by POI are erroneous.