Missing import filter

I am trying to use Koffice and my Excel files. I am using Kspread 1.1 (RC1). I can open My excel files with Staroffice, but when I am using Kspread Iget this message: Missing import filter. Could not import file of type application /x-xls. But I can not find any application to konfigure in Kspread. I am using SuSE 7.2 prof. GunnarH