[Plugin: UserAgent Theme Switcher] Theme Switcher issue

It seems that if I try to update an existing theme after I’ve activated this plug-in and set up the plug-in to use different themes per browser, I cannot modify widgets, menus, etc. of any theme. Its stuck on the theme it was set to when plugin was activated.

Not sure what the issue is.

http://wordpress.org/extend/plugins/user-agent-theme-switcher/