Hi Diana,
I’m using WordPress 3.6
I’m using Category Posts in Custom Menu version 0.8
I’m using the TwentyEleven theme
The plugins I’m using are: Akismet, Contact Form 7, Custom CSS Manager, Custom Meta, Dropdown Menu Widget (not activated), Jetpack by WordPress.com, My Category Order, Simple Rich Text Widget, Styles, Styles: TwentyEleven, TwentyEleven Theme Extensions, and WYSIWYG Widgets.
I have no idea how to use your plugin without having a theme.
Yes, I deactivated every plugin except yours with no change and then re-activated them one by one.
Thanks,
George