Hmmmm... I thought the battles of Valkyrie Profile weren't playable (severe framerate drop) on ANY psx emu, EXCEPT vgs !!
...unfortunately, vgs has some other issues with this game (cannot display world map properly - it crashes the emu) so you need to use a special patched version of vgs to play the game.
I know it is bad that such an excellent rpg cannot be properly emulated on any emu yet, but lets keep our hopes high and our fingers crossed - ePSXe is a near-perfect emu, and maybe in the next version this game will work !!