Same problem here, really nobody knows?

I just discovered, that is has something to do with a player's level, and dexterity (<90). Anyone has got farther?
EDIT: Seems it only affects ranged skills (not all of them), so it may mean ACCURACY? I'm sure the calculation is included in the client, too (how else would it count the skill damage values). But where to search for it...
EDIT: Can't find anything even in the decompiled client... :/