BuddyPress.org

I'm using the set up where it makes it

blogname.sitename.com



if that matters

If it does, how do I change it so that it's

sitename.com/blogname

My money is on that; I don’t think Hostpapa supports wildcard subdomains.

AS A TEST, backup everything and delete all your WPMU/BP files and empty the database. Reinstall, but this time during WPMU installation, pick the style of install that’s “sitename.com/blogname” as opposed to the one with subdomains.