I was having a similar problem i had the Activate page as a sub page to the Members area.
Two things you might want to check.
1. Make sure your Activate page is set to Activate in the BuddyPress > Pages
2. Go to your Activate page under Pages > All Pages (if you don’t have one create one with no parent) make sure you don’t have it under a different menu as a sub page if you see a – Activate that means you have it as a subpage. it needs to be named Activate and with no parent.
