I have noticed with a few weapons although the only one I can name off the top of my head that has different stats in game then it says on the Website is the Grosse Messer.  (Phew, what a run-on)
http://c-rpg.net/index.php?page=equipshop&cat=onehanded#!?page=itemdetail&id=3196If you notice on the site it stats 1 weight.  In game the Grosse Messer has 1.2 weight.
It may not seem like a big deal, but weight makes a big difference for one handers, especially weapons with cut damage.  The weight could make the difference between a glance and a hit.  Hence why I use the Langes (One of the heaviest 1h swords)
Note: I believe my theory of weight is true, although this is personal experience.It is not a huge deal considering its easy enough to go into duel and check all the "Real" stats.  Although, if this could be fixed it would make me smile.