[Plugin: Sidebar Login] Not showing logged off on Firefox Vista

On Vista Firefox when I click logout, the page does not change, it still shows me logged in. When I try to access dashboard however, I am indeed logged out and redirected to the WordPress login page. (Any way to keep this on my main page)

On my XP machine, Firefox, I get logged out and redirected to the same page (as desired).

Here is the URL:
https://www.grapethoughts.com

Thank you.

Judy