Which editor are you referring to? The default WordPress Post and Page TinyMCE WYSIWYG Editor or some other editor that comes with a theme or plugin?
To eliminate or confirm that BPS is causing the problem and/or to isolate which BPS security feature is causing the problem do the troubleshooting in the link below and post the results of troubleshooting.
http://forum.ait-pro.com/forums/topic/read-me-first-pro/#bps-pro-general-troubleshooting