Slow compdump on Vista - no .zcompdump created

["John Cooper" <John.Cooper@xxxxxxxxxx>]

Each time I start cygwin zsh (4.3.2 or 4.3.4) on Vista, compinit takes
around 12 seconds and no .zcompdump file is created:

C:\>zsh -f
$P$Gautoload -U compinit
$P$Gcd
$P$Gdate; compinit; date
Wed Oct 24 13:56:08 GMTDT 2007
Wed Oct 24 13:56:20 GMTDT 2007
$P$Gls .zcompdump
ls: .zcompdump: No such file or directory
$P$G

"compinit -u" and "compinit -C" take about the same time.


With zsh 4.2.6 on WinXP, when I run "compinit" I get prompted:
  Ignore insecure directories and continue [ny]?

(this prompt isn't shown with zsh 4.3.{2,4} on Vista.)

If I type "y" or run "compinit -C" it runs much faster in zsh 4.2.6 on
WinXP (although a .zcompdump file is still not created):

$P$Gdate; compinit -C; date
Wed Oct 24 14:08:16 GMTDT 2007
Wed Oct 24 14:08:17 GMTDT 2007
$P$G

Any ideas on how to speed it up on zsh 4.3.4 on Vista, and why the
.zcompdump file is not being created (`man zshall' states it should be
created by default)?

Thanks,

    --- John.