This appears to have been an issue with the DNS settings... I could always get to the site at http://ribbonbylulu.mycafecommerce.com, which can tell you if it is a problem with the code on the site or with the DNS... I reported it to Dreamhost and they seem to have resolved the DNS issue immediately, as I can visit the site now.
I'm asking them what caused the problem in the first place and will report back to you when I get word on what is causing this issue.