export excel problem ireports 3.7.4

Hi,

We evaluate now ireports and jasper reports, we are in the first stage off evaluation. There is something that i not understand, when i export to excel and ods the nummeric fields are given as text. We can not calculate with this fields. So i came up with this, in the options pane, export options you have the auto dectect cell type I turned this on but the result remains the same. I played the last 3 days with ireports and this is thy only issue that is blokking me to give a demo.

What can i do to solve this problem? Many thanks.

Best regards,

Christiaan.