Non wp_ tables NOT showing up as back-up-able with Snapshot

Just installed snapshot and network enabled in my multi-site environment. It only shows up in Network Admin mode, which is fine. When I go to do a backup of the main site (the only one that exists now), it does a fine job of backing up the wp_tables, but does not give me the option of backing up other tables. In particular, I have Buddypress installed.

Any ideas?

Thanks in advance.

Andy