After the connection is established OpenVPN shows a little popup with a 10.x.x.x IP, is this normal?

Yes, it is! That is the INTERNAL IP and meaningless.

Only worry about the assigned IP that is shown in the Members Area. (for Dynamic subscriptions even that assigned IP is unimportant, since it will be randomly picked at the connection routine and is unknown to the Members Area)

To verify a successful IP change check the header on top: http://forum.nvpn.net