I have noticed on several sites using Events+ plugin that some of the WordPress admin styles get messed up due to the jQuery UI CSS being loaded by the plugin. I've seen this with other plugins that use the jQuery UI CSS too.
Basically, some of the elements in the WP Post Editor conflict with this jQuery UI CSS - the close "x" button in the top right hand corner of the popover window when adding a link to a post gets duplicated, for instance.
This is resolved by removing jQuery UI CSS related lines in the plugin, i.e.:
wp_register_style('eab_jquery_ui', plugins_url('events-and-bookings/css/smoothness/jquery-ui-1.8.16.custom.css'), null, self::CURRENT_VERSION);
Is this a common problem, and is there a more elegant solution than stopping the plugin calling jQuery UI CSS?