Hi Gita,
I checked the export options in i5Grid in 14.0 SP05 and SP06, in both the behavior is as you have explained.
I tried by setting RowCount dynamically in the html page. The grid shows the right number of rows/data, but the same doesn't get applied on export.
This is a bug, and is corrected in MII 15.0
Thanks and Best Regards,
Ria