The plugin 1.0.4 affects the autosave function of wordpress.
While using the editor in WP the "Update"-Button normally gets greyed out when autosaving and then becomes active again.
With WPPTPE activated the button most of the time stays greyed out.
You'll have to copy the whole text, press F5, re-insert the text and save quickly before the autosave comes along.
I have to inactivate the plugin when I'm going to edit any site content.
Sometimes I also get an "out of memory" error for a php file in the plugins folder when saving a file, maybe it's the same issue.