I put some o-ring lubricant (from the local pool store) on mine and it is smooth as silk. I would imagine that the lubricant protects the o-rings too.
Real good folks too!! Worth paying a bit extra for. 
D' Oh!!  I, too, am a fan of these matchboxes.  My only complaint was that the double o-ring closure would be hard to open if you had to do it one-handed.  But then I have never graced my o-rings with lubricant.  Guess I will have to try that.  Thanks for the tip!
I agree, they are well worth the money.