How does this amazon.com/mom thing work with coupons???

smiling76

So I signed up for amazon.com/mom a couple weeks ago and used my $10 coupon and 20% off diaper coupon plus did the subscribe and save and only paid $8.50 for like 180 diapers---what a steal!!!!  But from reading blogs it sounds like you just cancel your subscription afterwards and then re-sign and you can use the coupons again (new coupons with new codes, but same offers). 

So I tried doing that today and it's not allowing me to use them on diapers----  I'm trying to use the 20% off diaper one and a $10 off any baby item one (doesn't say it excludes diapers).

Any ideas what I'm doing wrong????