Hi Michal,
I think there's really nothing you can do with the action of the LT3, I'm afraid... I really cannot remember where exactly but it was stated somewhere that the compression lock on these particular models weren't that smooth compared to Goldens and Taichungs.
I know this, because I've had two LT3's, and no matter how much I clean and lube the PB washers, it just doesn't drop shut as other comp locks. All other aspects of the knife, I like very much especially the chamfering on the g10 handles - completely blows away the PM2s and P3s in terms of grip comfort.
Edit: also for what it's worth, getting this with additional shipping from forwarders and sales taxes, wasn't exactly cheap also on my side of the world. Still a great knife despite the flaws.