I know we've touched on this before here on CW.
I'm having a difficult time expressing to the OP exactly why her Catholic parents are saying they will not attend her secular ceremony thus an invalid marriage. She wants to know if she should press the issue with them.
I was hoping someone from CW who is a bit more eloquent could help.
http://forums.theknot.com/Sites/theknot/Pages/Main.aspx/wedding-boards_etiquette_would-it-be-polite