I’m using a bit of a hybrid cbox, monitoring and pulling some plugins from the project from a sandbox install to use on my established multisite instance, so I’ve already taken the leap and updated to BP 1.7. The Groupblog plugin adds a “blog” link in the group that you can configure. If this is set to redirect to the homepage of the group blog, it redirects instead to the wp-admin (dashboard) of the main domain. I’ve posted this issue in the WP.org forums as well (here: wordpress.org/support/topic/redirect-goes-to-wp-admin) but it doesn’t look like a monitored forum. I thought I would give you all a heads up before you update.