Affiliate referals not being recognised/Membership Plugins

Here we go!

1. Installed membership and affiliate plugin
2. Created a new test member (me with a second email address/username, et.c), using the register form, also went through the payment gateway no problem
3. Used the affiliate link for this new user/member to create a third user/member.
4. no recognition provided to the affiliate that a new user has signed up though them.
5. membership is activated in the affilaite plugin
6. Have tested with cookies cleared and in different browser

Summary - when a user refers someone to the site through their affiilate link, the referral is not recognised.

Presumably I've missed something along the way? My site is a simple single wordpress installation which will be accessed by a monthly membership fee

Hel po sorting this would be appeciated

THanks

Phil