Index: win32ss/gdi/eng/ldevobj.c
===================================================================
--- win32ss/gdi/eng/ldevobj.c	(revision 71866)
+++ win32ss/gdi/eng/ldevobj.c	(working copy)
@@ -122,6 +122,12 @@
 
     TRACE("LDEVOBJ_pdmiGetModes(%p, %p)\n", pldev, hDriver);
 
+    /* Mirror drivers may omit this function */
+    if (!pldev->pfn.GetModes)
+    {
+        return NULL;
+    }
+
     /* Call the driver to get the required size */
     cbSize = pldev->pfn.GetModes(hDriver, 0, NULL);
     if (!cbSize)