GreenPoints is generally good, but obviously underestimated the demand for AA certs. I don't know about DL certs, but hope that they have enough in stock.
An "error" happened to me also when I shopped with Sparks.com: instead of crediting me with the actual amount spent, they credited me with the amount of the bonus certificate also. Of course, I won't complain about it.
I have the problem with Sparks.com: instead of crediting me with 200 clickmiles, they credited me with 100. I have to call them to fix that.
I want to have the new price for the certs also, unfortunately my DL certs arrived long ago.