Star Ocean 3 Significant Slowdown

[saya1314520]

i am playing star ocean 3
and i use soft render mode
it work well , fps 50~90
spec:
Quad 9450 @ 3.65Ghz

but i found a new problem , when i play to "Urssa Lava Cave" , i need press different "X" to play flute.
but i cant press weak "X" , only big "X"
anyone can help?