CK doesn't include closed accts for aaoa so it's possibly way off.  How old are your current accts?  Do you have any old/closed accts reporting?  Also, with a 595' i'm assuming you have some baddies on your report.  Getting rid of those will help your score much, much more than another couple secured cards.  Adding a couple more secured cards *could* be helpful at some point, but right now you should focus on those baddies, imho.