BuddyPress.org

@tim-watt Here you go:

In your theme’s /style.css, find line 1544 where you see this
div.post .wp-caption {

Go down to where you see the margin settings and change them to this:
margin: 0 20px 20px 0;

That should do it. If you’re running Firefox (and I really hope you are) install Firebug for Firefox. Finding stuff like this is a snap with that tool!