Interactive Reporting - conversion error when export to excel

Hi,

in CRM 7.02 in Interactive reporting we have in each report buttons for export to CSV and export to excel.

eg. role Marketing manager -> reports -> Campaign effectiveness -> Export to CSV (button).

then I get in excel file only characters like:

‹ ˙ťTËnÂ0 ś3_rç‘ U=Ą xĂ !h«H- ř~†Č
ql Yٵě™ŮÝxµ ěđŹ3m&#136;_ ŃÄ _°đÁo† Ú<9á‡6 ?âBäž6–bVřćÍ9AĆÉ^†šđf‡CĹíśü‡BÄ(Wę„ôa¦ŐŔ'}€ şąĺ˘/´<ዶŠ5¨Áň`×b9 áf

Can you please put any ideas on how to solve it?

Regards

Radek