Comment 29 for bug 49740

In the 1.6.0 sawfish release notes is the comment below; since we're still on 1.5.3 this looks like an upstream bug with an upstream fix - and our sawfish packages are ancient.

Dave

From http://sawfish.wikia.com/wiki/News
  - Random window disapperance prevention

          There're reports of sudden, random window disapperance, under
          Xinerama and some other drivers. It is partly prevented, but
          not completely, as this may also be caused by other libraries
          or buggy video drivers.

          Now in error_handler() in src/display.c, when a window sends
          request_code 12 (X_ConfigureWindow), don't auto-assume it to
          be unmapped. [Janek Kozicki]