This is what I did to test to make sure it was working.

I added $25 gift cert to cart and checked out. Sent the gift cert to myself via email for $25.

Once I logged into my email I clicked the link to redeem my gift cert. I added a $20 item to cart. During checkout I put in the redemption code from my email and entered 20.00 for the amount I wanted to use. When I hit continue it gives an error that the redemption code is invalid. I tried this several times and still the same result.

I dont understand why it wont work. Any ideas?