I've written some into my Algo FAQ, but suffice it to say... there's a ton of bugs.
Although, Flans have an evasion bonus of sorts as you lose a multiplier or two when trying to hit them physically (it's hard to actually notice this at higher levels until you get the overpowered weapons).
You should have researched it a bit first. Then you could have (as another poster stated) tracked down the European version of the game, with fixed glitches.
There are places you can get it from online. I can't use the proper word for "it" on here for legal reasons. But if you'd like me to contact you about it (assuming you don't already know what I'm talking about, and how to get it) I would be glad to show you or just provide you "it" myself ;)
Love this game, in any case (never played this GBA one in particular, though; I just know all about it).