pb editing text including "import" word

Hi all,

I use FCKeditor 2.6.3 version (build 19836)
Everything worked correctly but today, I had a strange problem for the first time.

If I use the word "import" in my text, FCKeditor crash my navigators (IE8 and Firefox 3)
If I use a word containing "import" ("importance", "importation", "important", ...) it crash my navigators too.

Did someone had the same thing ?
Do you know how to solve it (without changing my text) ?

Thanks very much !