Hmm, I'm afraid this looks like a platform issue on your server. There is no escaping done by OCS upon saving or displaying the form, so between the script being sent to your server and OCS receiving it on the PHP side, some escaping is getting done. This is usually "magic quotes" or similar but you report that this is disabled. A work-around that could get you un-stuck, at least: try editing the contents directly in your database (in the plugin_settings table). This is easiest done using something like phpMyAdmin. Before you try it on the OCS side, make sure you flush your OCS data cache.
Public Knowledge Project Team