Started to do a let's play for the GBC version to document the differences from the NES one... and I get this same problem.. Get to Brynmaer, Glitch up. Sometimes if i run really fast, i can run from 1 area to another without glitching.. but this seems to happen in all areas in 1 particular song playing... And not so good for a let's play xD;
So anyway, I remember back in 2001, i played and beat this game 100% fine without errors.
I'm a hoarder, and i never delete anything.. So i go back, and find out i was using VBA 1.1 ( VisualBoyAdvance-1.1.zip )
Tried it out, works perfectly.
Just wanted to put this out there since I'm sure people in the future will check out Crystalis for GBC and come across the opcode issue