Personally, I think that is bad advice. Every small shop owner that decides to accept bitcoin should NOT be forced to run a full bitcoind node on their server. If that were the case bitcoin would fail. Bitcoin needs 3rd parties and lite clients to make the process easier for integration. Blockchain.info API offers an amazing service absolutely free. Yes it does go down from time to time, but the trade off is well worth it. I can register a website and hosting and start accepting bitcoin on my new website using blockchain.info's API in a few hours. No time needed to download the blockchain and no extra bloat to my servers bandwidth from having to run bitcoind.
As for the OP's question, sounds like bc.info is having some tech difficulties with the payment forwarding. The receive payments API should come back shortly.
Ive gotta agree, i found some priceless blockchain.info api tutorials on youtube that were very empowering ..(ahem)! After i found those tutorials my interest in bitcoin and php has gone up 300%! I didnt have to get a vps or a dedicated server .. just got a domain and a run of the mill hosting account and i was off to the races. If anything we need more dependable third party services like the one icanscript mentioned above. These guys look great too.. https://chain.com/
@ icanscript : thanks for the link. I was checking out the documentation at blockcypher.com and found this lil gem. http://dev.blockcypher.com/#zero_confirmations
Ill be taking a closer look at them when i get a chance.