Case-insensitive completion problems with Cygwin 1.7

["John Cooper" <super.cooper@xxxxxxxxxxxx>]

I've just upgraded to Cygwin 1.7 (and zsh 4.3.10) and found that
case-insensitive completion no longer works when the path starts with a
drive letter.

If I start off with `zsh -f' file completion works as expected even when
using a drive letter:
$ ls /c/<TAB>    # works as expected
$ ls c:/<TAB>    # works as expected

However, after running the following (to allow for case-insensitive
completion):
  zstyle ':completion:*' matcher-list 'm:{a-z}={A-Z}'
  autoload -U compinit
  compinit -C
$ ls /c/<TAB>   # still works as expected
$ ls c:/<TAB>   # fails - no completions are listed

Previously I was using zsh 4.3.2 running under Cygwin 1.5, and I used to
additionally have the following lines in my .zshrc:
zstyle ':completion:*:paths' accept-exact 'c:' 'd:' 'b:' 'o:' 'w:' 'r:' 'v:'
zstyle ':completion:*' fake-files '/:c' '/:d' '/:b' '/:o' '/:w' '/:r' '/:v'

This allowed completion to work when using drive letters in zsh 4.3.2, but
it doesn't work with zsh 4.3.10 and Cygwin 1.7.

Is there any other way around this, so that I can still perform
case-insensitive completion using c:/ ?

Btw, my /etc/fstab contains the following, which allows me to use /c/ rather
than the default /cygdrive/c/
none / cygdrive binary,posix=0,user 0 0

Thanks,

    --- John.