How "random" is random Chess960?

Even if my opponent or I choose "random" Chess 960, we always get the same array of pieces (knights on files a and b...bishop on file h). Is this because we are requesting rematches, or does Chess 960 have this fixed assembly? (If so, is there another way to truly randomize the starting positions?)

Not a clue, click on Help & Support at the bottom of the page and contact the staff directly with your question. 

I doubt if my blog will help but check it out anyway maybe using another browser or doing some other fix for IP problems in general might help, if not you won't mess anything up.

http://www.chess.com/blog/NimzoRoy/diagnosing-and-fixing-internet-problems?_domain=old_blog_host&_parent=old_frontend_blog_view 

http://support.chess.com/Knowledgebase/List/Index/16/chess960

It's because you're requesting rematches. That way you can play white and black with the same position. To get a new position start a new game.