Where do you turn when you need this kind of information?
when in doubt, I toddle on over the whois.net or good 'ol networksolutions.com (NSI).
I don't register throught NSI but I find when I register a domain with another registrar and check immediately with NSI my new domain correctly comes up as unavailable.
Love 'em or hate 'em they do seem to have it together when a domain is unavailable; sometimes TOO together!
Onya
Woz