Chip,
This is exactly how I have the limits set (plus the estop). All are wired in series. All NC. If I hit one of the limit switches (with my finger), all the LEDs light in the configuration window. If I let go, they go out. But it won't reset. It says "external estop requested" and scrolls "press reset...emergency mode active".
Here is the port 1 pin state in the configuration window (x=on, o=off):
ooo*********oxoooo
oooooooooooo
If I hit the limit switch (capital X comes on):
ooo*********Xxoooo
oooooooooooo