Hi, First I had to use Spreadsheet::WriteExcel::Big otherwise the script was failing, That is, above a certain number of sheets, whatever their size one need to use the Big version of S::WE. I also set the maximum number of iterations to 2048 instead of '1025'. Unfortunately, S::WE did not complain. It accepted all of our requests, that is, creating 2048 sheets. The resulting workbook was desperately *empty* :( . Also no warning was generated. So I decided to find the maximum number of sheets below which the resulting file is empty. The result being that as soon as you are above 250 iterations (sheets), the 'multi.xls' become empty. An absolutely no warning is generated. That is, for 251 sheets to 2048 sheets (and more) the resulting workbook is empty (no warning). Here are the other information you requested: OS version: SunOS 5.8 sun4u sparc SUNW,Ultra-5_10 Solaris Perl version: v5.8.3 built for sun4-solaris-thread-multi HTH.