ainuan, you are actually seeing the problem i've heard that many before you have faced. your ranged weapon level isn't keeping up with your character level. there's two choices... really work on that ranged weapon skill (any time the last hit of a monster can be done with a ranged instead of melee, use the ranged... or kill the higher hp monsters entirely with ranged... or both) which will hopefully bring the weapon up to your lvl, but you will contantly have to do this stuff now to maintain the ranged skill level. the other option is to just hold on to the previous level's weapon, until you do level it, then upgrade the ranged and use it (until partway through the next level when it finally upgrades to the next level), and so on. hope that helps.
--jason
