bug#3252: 23.0.93; extremely slow to open file on windows network drive

Opening a file on a windows share by dragging it from Explorer and 
dropping it into Emacs takes many many seconds.
Doing the same operation on Emacs 22.3.1 is almost instantaneous.
The file is in a large subversion 1.6 checkout, which may or may not be 
relevant

In GNU Emacs 23.0.93.1 (i386-mingw-nt5.1.2600)
  of 2009-05-02 on SOFT-MJASON
Windowing system distributor `Microsoft Corp.', version 5.1.2600
configured using `configure --with-gcc (3.4)'

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: nil
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: ENG
   value of $XMODIFIERS: nil
   locale-coding-system: cp1252
   default-enable-multibyte-characters: t

Major mode: Fundamental

Minor modes in effect:
   shell-dirtrack-mode: t
   cua-mode: t
   tooltip-mode: t
   mouse-wheel-mode: t
   menu-bar-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   blink-cursor-mode: t
   global-auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   line-number-mode: t
   transient-mark-mode: t

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