Why is my attack on maplestory going down?

Okay, I am a level 42 in on maplestory (server windia). When I was level 41, my weapon attack was 239-399. But today, I leveled up, and my weapon attack went DOWN to 232-372!!! Is my game glitched? Please help me, cause I'm worried that if I level up any more, my weapon attack will go back down to 100!