'ediff-buffers' on ubuntu netbook edition

[Tom Roche <Tom_Roche@pobox.com>]

summary: when running `M-x ediff-buffers` on 23.1 on ubuntu netbook
edition, buffer="*Ediff Control Panel*" is

+ visible
- not reachable from the OS
+ reachable from emacs via `C-x 5 b`

Is there a workaround? Is this a known bug?

details:

I'm running

$ emacs -q --version
GNU Emacs 23.1.50.1 # ubuntu package=emacs-snapshot-gtk
$ lsb_release -ds
Ubuntu 10.04.1 LTS # 32-bit, Gnome, with Ubuntu Netbook Edition
$ uname -rv
2.6.32-24-generic #39-Ubuntu SMP Wed Jul 28 06:07:29 UTC 2010

On my other cygwin and non-UNE ubuntu boxes, I often run
'ediff-buffers' with the buffers in side-by-side windows. I then
Alt-Tab to the control buffer, and hit SPC or whatever to control the
merge, and eventually 'q' to exit.

I'm setting up this UNE netbook, and wanted to merge some config
files, so tried to do the same thing. I unmaximized my single emacs
frame, did `C-x 5 f` to open the other version of the file, sized them
evenly on R-L halves of the screen, and did `M-x ediff-buffers`. The
control buffer popped up in an approximately normal place on the
screen, but

- there were still only 2 emacs icons at the upper left of the screen,
  where open windows register, instead of 3 as normal.

- I could not Alt-Tab to the control buffer.

After fiddling awhile, I found I could `C-x 5 b` to it, however, and
control the merge that way.

I'm wondering, is this a known bug? If known, is there a workaround?
Apologies if this is a FAQ, but googling on some variations of

emacs "ediff-buffers" "ubuntu netbook remix" OR "ubuntu netbook edition"

got no hits. Feel free to reply directly to me as well as the list.

TIA, Tom Roche <Tom_Roche@pobox.com>