I think i have found a little error in the logoff page, while trying to apply a css file to my whole site through the theme capability from asp.net

I created my css in a new theme, and applied it by default to all pages to make the site hot (or at least fire it up a bit)
However, when i later clicked on disconnect, the logoff page threw an exception, telling me that it had no element. Indeed, the Logoff page was totally blank, and i just had to set the html, body and recommended head tag to have it running smoothly
Is it something that was overlooked, or a way to avoid theming, or am i doing it wrong (although i do have the feeling that users should be allowed to theme the site the ASP way)?

Thank you for your answer,

Best regards,
Samy

ps to forums admins: although the problem concerns themes, i'm not sure it's supposed to be posted there. I hope it won't be a problem