Can't start X on MS Windows 7

["Harvey Stein (BLOOMBERG/ 731 LEXIN)" <hjstein at bloomberg dot net>]

I'm trying to run X under MS Windows 7 within Cygwin.  I bring up a bash window, run startxwin & I get:

waiting for X server to begin accepting connections .
..
..
..
..

and it never starts up.  An X icon appears on the toolbar & then disappears.  XWin.exe shows up in the task manager & doesn't exit.  I searched the mailing list & found the suggestion of wiping out the full installation & reinstalling, but I'd rather avoid that.  Any other ideas?

Output (which appears to match /var/log/xwin/XWin.0.log):

$ startxwin

Welcome to the XWin X Server
Vendor: The Cygwin/X Project
Release: 1.14.0.0
OS: CYGWIN_NT-6.1-WOW64 NY731-3W-143A 1.7.17(0.262/5/3) 2012-10-19 14:39 i686
OS: Windows 7 Service Pack 1 [Windows NT 6.1 build 7601] (WoW64)
Package: version 1.14.0-2 built 2013-04-11

XWin was started with the following command line:

X :0 -multiwindow

Initializing built-in extension Generic Event Extension
Initializing built-in extension SHAPE
Initializing built-in extension MIT-SHM
Initializing built-in extension XInputExtension
Initializing built-in extension XTEST
Initializing built-in extension BIG-REQUESTS
Initializing built-in extension SYNC
Initializing built-in extension XKEYBOARD
Initializing built-in extension XC-MISC
Initializing built-in extension XINERAMA
Initializing built-in extension XFIXES
Initializing built-in extension XFree86-Bigfont
Initializing built-in extension RENDER
Initializing built-in extension RANDR
Initializing built-in extension COMPOSITE
Initializing built-in extension DAMAGE
Initializing built-in extension MIT-SCREEN-SAVER
Initializing built-in extension DOUBLE-BUFFER
Initializing built-in extension RECORD
Initializing built-in extension DPMS
Initializing built-in extension X-Resource
Initializing built-in extension GLX
(II) xorg.conf is not supported
(II) See http://x.cygwin.com/docs/faq/cygwin-x-faq.html for more information
LoadPreferences: /home/hstein/.XWinrc not found
LoadPreferences: Loading /etc/X11/system.XWinrc
LoadPreferences: Done parsing the configuration file...
winDetectSupportedEngines - DirectDraw installed, allowing ShadowDD
winDetectSupportedEngines - Windows NT, allowing PrimaryDD
winDetectSupportedEngines - DirectDraw4 installed, allowing ShadowDDNL
winDetectSupportedEngines - Returning, supported engines 0000001f
winSetEngine - Multi Window or Rootless => ShadowGDI
winScreenInit - Using Windows display depth of 32 bits per pixel
winAllocateFBShadowGDI - Creating DIB with width: 2560 height: 1440 depth: 32
winFinishScreenInitFB - Masks: 00ff0000 0000ff00 000000ff
winInitVisualsShadowGDI - Masks 00ff0000 0000ff00 000000ff BPRGB 8 d 24 bpp 32
winInitMultiWindowWM - Calling pthread_mutex_lock ()
winMultiWindowXMsgProc - Calling pthread_mutex_lock ()
MIT-SHM extension disabled due to lack of kernel support
XFree86-Bigfont extension local-client optimization disabled due to lack of shared memory support in the kernel
GL_VERSION:     4.2.0
GL_VENDOR:      NVIDIA Corporation
GL_RENDERER:    NVS 310/PCIe/SSE2
(II) AIGLX: enabled GLX_SGI_make_current_read
(II) AIGLX: enabled GLX_MESA_copy_sub_buffer
(II) AIGLX: enabled GLX_SGI_swap_control and GLX_MESA_swap_control
(II) AIGLX: enabled GLX_SGIX_pbuffer
(II) AIGLX: enabled GLX_ARB_multisample and GLX_SGIS_multisample
(II) 482 pixel formats reported by wglGetPixelFormatAttribivARB
(II) AIGLX: Set GLX version to 1.4
(II) 359 fbConfigs
(II) GLX: Initialized Win32 native WGL GL provider for screen 0
[dix] Could not init font path element /usr/share/fonts/TTF/, removing from list!
[dix] Could not init font path element /usr/share/fonts/OTF/, removing from list!
winPointerWarpCursor - Discarding first warp: 1280 720
(--) 3 mouse buttons found

waiting for X server to begin accepting connections .
..
..
..
..
..