Interesting the 25-32 Conti's I just purchased most definitely do.

I got a CO2 inflator for if I have a puncture, and I did a practice with a gas cylinder and no matter how tight I did it up, it came out when I unscrewed from the inflator.

Don't want to go through this on the side of the road, so will check out the ones mentioned. Anyone know on Speicalized.