Coupons in Membership Don't Seem to be Working...

Ok, Wordpress 3.4.2 (single site)
Latest version of Membership
Using Paypal as gateway.

So, unlike numerous other posts over the last few months about admins creating coupons but them not showing in the Admin dashboard - that is fine for me.

My (apparent) issue is that it seems like the coupon never gets validated when a user is signing up.

You can put in a bogus code, click the Apply Coupon button, and then the form shows "Using Coupon Code: <garbage code>" the same as if the code is good.

Continuing through the payment wizard - there is NEVER any indication that the coupon is actually applied. After entering the code and clicking the "sign up" button, the next screen ("Sign up for <Level XYZ") offers not indication of coupon in use.
Clicking "Subscribe" button correctly takes us to the Paypal "login to complete your checkout" screen, which also still reflects the non-couponed price (ie - full price).
Signing in to your Paypal account so as to finalize payment STILL reflects the full membership price...???!

Clicking "Agree and Pay" applies the full charge to your Paypal credit card / account...??

So, what up?