I recently decided to replay this game and I figured out a "glitch". As I came close to Hargon, I decided to change my weapon to Thunder Sword (from Falcon Blade), but then I canceled (pressed B) the decision, so I was still wearing my Falcon Blade. The interesting thing is... I am now equipping my Falcon Blade but with the power of my Thunder Sword, meaning twice the maximum power. I have no idea how I did this even though I have described my rough procedure, but I cannot recreate the same glitch again.
Double post, but something I remembered about the cursed equipment glitch is you can't level up or view your stats. My only guess is try it again but go straight into battle without viewing your stats, if you haven't done that already.
"I don't really have anything to add, I just wanted to say that I lol'd. Hard." - Esquire J
That's the weird thing here. I can view my stats, and it will say I have Falcon Blade equipped and still have the attack power of Thunder Sword. I happen to have a save state saved right before realizing this, but I cannot recreate this glitch.
I haven't tried leveling with this glitch on since I just wanted to finish game and play DQIII... but maybe it'll change it back.