Wrong Walue Weapon?!?

I have one question about concrete weapons: when i have equiped weapon "Mighty Lifethief of Potency" - (58.8 damage; 21 strength; 11 Inteligence. Charged attack heals 15% fo damage done) i made a damage about 100 - 200 per hit! When i equip "Agile Heartseekers of Brutality" - (77.9 damage; 11 strength, 21 dexterity. Chance to cause target to bleed) i made a damage about 35 - 70!!! One more thing, strength is not important for rogue to have a high damage, but dexterity.

All my profile statistic went green and become much higher with the second weapon, but on the field was completely different! I start switching weapon during battle, and how is bloody possible that weapon which lower all my statistic down and with lower damage (on the paper) deal a lot higher damage in battle? Even the critical strike with better weapon was smaller than normal attack with worse weapon.

Does any rogue noticed that, or this is "bug" only on mine character? Im not willing to lower my statistic down, but also im not willing to equip a better weapon statistic, and deal damage such an average warrior! Any solution?!? Can anyone fix this?