BuddyPress.org

If your using a theme other than buddypress default within a child theme then things are gonna break when if you copied the bp-default themes style.css into your active theme. If your using a child theme based on something else then you need to add adjust and add this to your active themes style.css

/*
Theme Name: Whatever you wanna name the child theme
Theme URI: http://example.com/
Description: Child theme for whatever theme you choose
Author: your name here
Author URI: the theme name you made a child them of "case sensitive"
Version: 1.0 or whatever you want to number it
Tags: whatever tags is appropriate if it is a a theme specific to buddypress then you will want to add "buddypress" to the tags sense 1.7 adding buddypress tag is not a necessity.
*/
/*-------------------------------------------------------------
Custom CSS
--------------------------------------------------------------*/
@import url("../whatever theme name you made a child theme of
"case sensitive"/style.css");

but once I add the buddypress.css file from /bp-legacy/css/ to /mytheme/css/ it breaks buddypress styles completely.

You may need to explain what your process in more detail. Adding /css/buddypress.css to both 2012 and a child theme based on 2012 works as expected.

@karmatosed Actually I got confused because I have various installations of WP and BP on my localhost. Actually on my WP 3.5.1 install and BP 1.7b1 install using a child theme of “Responsive” I just use my child themes style.css to overide any buddypress css that I need too. Reason I do this is so if the “Responsive” theme gets updated then my child themes styles stay intact. Make sense?

@cikez did you copy the buddypress css directory folder as well as its contents to the root of your theme? If I am correct it needs to maintain its directory structure so in the root of your theme if you copied it correctly there will be a folder named css and inside it will contain buddypress.css

@cikez Sorry but I am not too familiar with Artisteer themes structure. Maybe someone that has experience with these themes can jump in to lend you a hand. My apologies!