bobthebanana:
I also thought that the value was lower than usual. But it seems to coincide with what Grumpy_Mike said. The datasheet, however, says 1.2mA is enough to pull it low.
No, the worst case inputs (S inputs) require -1.6mA when low. Thus to bring below 0.8V you need less than 500 ohm pull downs, to bring down to 0.4V suggests less than 250 ohms (you do want noise immunity!).