Frame title problem

[Stephen Berman]

The X Window title bars of my Emacs 24 builds have an oddity: no matter
what the value of frame-title-format is (including nil), the title bar
always displays the string " <@escher.home> " at the end (unless more
than one Emacs frame is open, in which case "<2>" follows that string in
one of the frames), where "escher.home" is the value of system-name.
However, I only see this frame title appendage under KDE, not under
icewm or twm (these are the only WM's currently installed on my system).
And, while I see this with an Emacs 24 build of 2010-09-08, I do not see
it with a 23.1.91 build of 2010-01-28 (the only 23.2 pretest build I
have).  These two builds differ in GTK+ version: 2.18.1 for the earlier
vs. 2.18.6 for the later builds.  But I also have an Emacs 23.1 built
with GTK+ 2.18.6 by openSUSE on the same system (I'm running 11.2 and
KDE 4.5.2), and this 23.1 build does not have the frame title appendage.
So this seems to be due to some interaction between Emacs 24 and
KDE/GTK+ (perhaps involving the gtk-qt engine), since I haven't observed
this with any application beside Emacs 24.  Do any of you have an idea
what could be causing this problem, or a suggestion how I could try to
track it down?

Steve Berman