Add several FCKeditor into an ExtJS Tabs with IE

Hello,

I've a html page with several editor. It's working fine with FF and IE like this.

I've added ExtJS Tabs.
I put my FCKEditor into a div with class="x-hide-display", and with ExtJS, i display these div into a tab.
With FF, i got posted data with one or several editor
With IE, i got posted data only if i've only one editor

How can i make work these editor with IE and ExtJS ?
Any idea about this bug ?
Maybe have you an How-To or a tutoriel ?

Thanks for help