[Eclipse]

I believe RiseUp works by re-directing it's traffic though one of it's servers. While your the traffic is going through their servers first, speedtest uses a flash object, which can give away your ip if you allow it to load.

The vpn might also be complete bollocks, haven't tried it personally

Hmm, interesting theory. Was the ip the same on speedtest.net as it was on whatsmyip.com?