Why does using threading.Event result in SIGTERM not being caught?

I have a threaded Python daemon. Like any good daemon, it wants to launch all of its worker threads, then wait around until it's told to terminate. The normal signal for termination is SIGTERM, and in most languages I'd hold to terminate by waiting on an event or mutex, so using threading.Event made sense to me. The problem is that Python's Event object and Unix signals don't appear to be playing well together.

This works as expected, terminating on SIGTERM:

import signal
import time

RUN = True

def handle(a, b):
    global RUN
    print "handled"
    RUN = False

signal.signal(signal.SIGTERM, handle)
while RUN:
    time.sleep(0.250)
print "Stopping"

but this results in no SIGTERM being delivered (i.e., quite apart from quitting, "handled" never gets printed):

import signal
import threading

RUN_EVENT = threading.Event()

def handle(a, b):
    print "handled"
    RUN_EVENT.set()

signal.signal(signal.SIGTERM, handle)
RUN_EVENT.wait()
print "Stopping"

So my question is:

1. Am I misusing threading.Event in some way?
2. If I am not, is there an alternative other than the poll-and-sleep mechanism from the first example?
3. Also if I am not, why does using threading.Event kill the signal handler?