I think a few people have noticed that the ERP plugin breaks the widget area within the admin panel.
This is because of a dodgy script [from line 200] in includes/widget-class.php within the plugin.
However, a quick and dirty fix is to chop out the script from the php file from line 200.
All it does is control the display of two text boxes dependent on the value of the drop down. I use this widget all over the place on on site I manage and I can live with having to remember which 'category numbers' to put in which box when using the plug-in.