Hello!  I've written a simple custom report source and i've added a bunch of columns to the rb_filter_option list.  When i go to create the report using this report source, i can see all of the columns i've included as options to add on the Filters tab.  When i select columns and click add, they show up in the list.. and then when i press save changes, they disappear.  If i try to add them in again, there is a javascript alert message that pops up in the browser that simply says 'Error' with no more information.   Has anyone seen this behavior before to know if there is something maybe i've done wrong?