I've used this plugin before and needed to delete it due to it interfering so much with Custom Post Types.
It comes to light especially now as I am using the plugin 'Magic Action Box' - http://wordpress.org/extend/plugins/magic-action-box/
In creating a new custom box, I found that when Post Type Switcher is installed, other content is treated as a Post, publishes out to my RSS Feed and generally corrupts the Custom Post Type function.
I installed this latest version and this behaviour is still evident.
I've got no idea what "Filter 'pts_post_type_filter' to adjust the boundaries." actually means either.
Since the plugin has no UI, I'm presuming this means that people need to go in and hack this plugin's PHP code - is that right?