Ispell not working in kmail

When I try to use the spelling tool in Kmail (after updating ispell using apt) I get this message: ISpell/Aspell could not be started. Please make sure you have ISpell or Aspell properly configured and in your PATH. There does'nt seem to be a way to configure ispell in Kmail and the man page is no help. Any ideas on how to fix this? Thanks, Jerome