I just updated last night and starting having this problem.  I updated earlier, possibly the day before, and didn't have this problem.

F:\emacs-build\cygwin\emacs\bin>.\emacs
Font `-outline-Consolas-bold-r-normal-normal-11-82-96-96-c-*-iso8859-1' is not defined


On Thu, May 15, 2008 at 2:44 AM, Kenichi Handa <handa@m17n.org> wrote:
In article <87skwkxov0.fsf@stupidchicken.com>, Chong Yidong <cyd@stupidchicken.com> writes:

> I have the following line in my .Xresources file:
> Emacs.Font: Mono-11

> This used to work, before the font-backend branch was merged in (I think
> it also worked for a time on the font-backend branch, but am not
> certain).  Now, however, Emacs won't run, with the following error:

> Font `Mono-11' is not defined

I've just installed a fix.

---
Kenichi Handa
handa@ni.aist.go.jp