Membership 2 upgrades staying in Pending

I have installed the above and it mostly works fine.
The only problem is when a new member attempts to create a new site from within the dashboard it diverts to the register screen (whether their level allows them to create sites or not). See the screen I'm referring to on attachment 1.
Also, when a member tries to upgrade they click the 'Change' button and nothing happens.
Their membership level changes to 'Pending' but they aren't notified in any way of this. Also, my membership levels are free, so it should just upgrade immediately.

Am I doing something wrong? (I usually am!)
Thanks
Duncan