LSMinimumSystemVersion

I tried using the Info.plist key LSMinimumSystemVersion to require 10.4.11. It doesn't work — even on 10.4.11, you're told you can't do that:

If I change the app to require 10.4.8 instead it works fine. I'm guessing that LaunchServices is using gestaltSystemVersion to get the system version, which returns 0x1049 for all of 10.4.9, 10.4.10 and 10.4.11... Perhaps Apple should follow their own advice about retrieving the system version...