What version of editor you use?
I can not reproduce this issue on the latest version. It works fine for me when I set cookieless="true" in web.config, like below
<sessionState cookieless="true">
</sessionState>
Environment:
I test on IE7, Firefox3.5, Google chrome and safari4.0 with IIS 7.
Is your site online? If so, can you send the test URL to me?
Regards,
Ken