I've observed a problem whereby a single-screen X11 session started
with startx or Xwin prevents a single xterm from being started in a
usable state (no keyboard or mouse focus), but the problem goes away
if the xterm is placed in a *particular area on the screen*.

It's a new fresh Cygwin install.

Here's the command I'm using:

startx /usr/bin/xterm

This opens a single-window X11 server populated with one xterm. Within
the X11 server window, the cursor is not visible and neither mouse
focus or keyboard focus is available.

Even with twm running, the situation is the same:

startx /usr/bin/xterm -e twm

Tested on:
Windows XP SP3 32-bit (running under VirtualBox on a Linux host,
1024x768 resolution, 32bpp and 16bpp)
Windows Server 2008 R2 64-bit (running under VMware ESX 3.x via an RDP
remote desktop session, 1132x778 resolution, 16bpp).

Here is the strange thing. On both installations I can get everything
working fine by running the xterm like this:

startx /usr/bin/xterm -g 40x40-xxx+51

with "xxx" set to 257 or more, up to an upper bound of 508, after
which it stops working again. This range seems to depend on the
horizontal resolution of the X11 server window, the example above
using 1024x768 32bpp, and basic testing seems to suggest that "xxx"
needs to be just over 25% of the horizontal resolution.

The vertical resolution of the X11 server window doesn't seem to have
a bearing on the issue.

So - it seems that the problem can be side-stepped by popping up an
xterm in the area of the screen just beyond the 25% mark on the
horizontal access, and then immediately closing it again, after which
everything is fine. The fact that it's such a repeatable error is
interesting!

Any insights appreciated.

Regards,

Patrick