may be just an isolated thing but I installed and ran the leap motion drivers and software then left it running while installing build 10780. the install froze and I had to kill it from the windows task manager.
I have not re-tried to reproduce the problem but it installed fine when I quit the Leap stuff. now it plays happily with the Leap Motion device via the leap motion CHOP.
just letting you know in case it is an issue elsewhere.
Rod.