Windows 7: Intermittent failure to resolve host aliases

I have Windows 7 professional x64 pc. I have another host running Linux, trixter.intranet.org, which serves several web sites, each with a different host alias: hg.intranet.org, svn.intranet.org, bugzilla.intranet.org, etc.

Occasionally, the Windows pc will be unable to find any of the aliased hosts, even when it can find the canonical name. The aliases will be un-resolvable for a period of several minutes, and then, with no intervention, they can be found again.

Trixter is also my nameserver, (bind 9.6.2-p2), the host aliases are defined with CNAME entries. Trixter can always resolve the aliases to itself.

Even stranger, when I use Cygwin from the problematic Windows 7 PC, it CAN resolve the hosts. I can ping hg.intranet.org from a Cygwin shell, but not from a “cmd.exe” window. Administrator privileges make no difference.

What could be the problem, and it there a way to fix this?