Waaaay bag in the day (2003ish) I had a set of early production Air Force 2 Hollowform LT forks which lost all of their pressure as soon as they went over a bump!
After several trips back and forth to Pace HQ where they has been tested on some sort of jig (allegedly) with no fault identified they eventually put them on a bike and rode them and confirmed their there was indeed a fault.
Oh, and they also sucked water in through the seals which they tried to fix but without much success.
Forks no longer in use (although they are still fitted to a bike in the fleet) but the Pace windproof top they sent to me as compensation for all of the trouble is still in regular use.