I've been using Quicksilver since I got my MacBook Pro a year ago. I have it set to use Modifier-only Activation with a double Function keypress. It has worked this way for ages, from Tiger all the way through my Leopard upgrade, and until today, and it has worked with both the laptop keyboard and 2 wired Alum. keyboards I have. Now the Modifier-only activation won't work for any of the key choices except "Caps Lock (Double Only). I haven't done any updates or changes to the OS today. I added a Quicksilver Custom catalog for a encrypted sparseimage bundle, and this behavior started after that. But I've deleted it again and still have the problem, so it may just be coincidence. If all else fails I may Reset Preferences and Run Setup again. Any other thoughts, suggestions, or insight?