fck don´t work under IE

I have a problem with fck editor working under ie!
wenn I use firefox anythink work perfekt, but under ie i get errors:

'FCKBrowserInfo' is undefined
'FCKLang' is undefined
'FCKConfig' is undefined

and so on.. but i don´t see anythin from the editor!!

but wenn I use firefox it run perfekt!!

could anyone help me please???

hatschi