[bitfolk] Diagnosing site problem

My site (ilovephilosophy.com) was down this morning, and I suspect that my registrar has fouled something up. I suspect this because nothing is wrong in Nagios, the site loads normally using the IP, and today was the day my registration would have expired had I not paid to renew it last week... Running tracert returns "Unable to resolve target system name ilovephilosophy.com" Running nslookup returns "*** UnKnown can't find ilovephilosophy.com: Non-existent domain" Is there anything else I can do to test my suspicion, or does any of this confirm it? I know it isn't just me or my network, because my users around the world are reporting the same trouble. I've as yet been unable to reach anyone at my registrar, and in the meantime I'm hoping to rule out any other possibilities. Thanks, Mike