Terminal title bar tweak discrepancy problem in Cygwin/X

Code for the tweak (not my fave 'running process' but the more popular 'working directory') :

case "$TERM" in
xterm*|rxvt*|rxvt-unicode*)
      PROMPT_COMMAND='echo -e "\033]0;$TERM: ${PWD}\007"'
        ;;
*)
        ;;
esac

Where it works: rxvt (the one I run 'rootless' outside of XWindows)
Where it doesn't work: urxvt (aka rxvt-unicode) inside Xwindows
(wm is Fluxbox, the 1.0.0 build that was contributed tangentially to the Cygwin folks; colorscheme is Leopard from Freshmeat, but I just tried some others and it made no difference)
How it doesn't work: urxvt's title bar, after the rest of .bash_profile loads and displays its wares, switches to a string of 6 non-printing characters (rectangles) and stays that way. I see "bash" until my Welcome.sh script loads, then the six npc's

Anyone know urxvt well enough to have a good idea as to why this tweak shouldn't work? I have some others that I've C&P'd from around the Web, and if this one is a dead rabbit, I'll just try one of those. On that score I'd need a hint as to what kind of code should work in urxvt.

TIA for all advice and suggestions.

BZT