"Command window with selection" not working - help?

[jgarbers]

For some reason I can no longer invoke QS with a text selection using
Cmd-Esc (or Ctrl-Option-Space, which is my usual hotkey for "Command
window with selection").  Pressing that key combination usually (but
not always) gives me a beep. Then there's a three or four second
delay, and finally the QS bezel appears with nothing in the left panel