Annoying sound lag

[chipxsd]

Is there any way to change sound buffer settings in ScummVM. There seems to be a sound lag on my FS Pocke Loox 720
It's very noticeable when Sam throws out that robot's head out the window and blows -- or when Bernard hits his head when going into the clock's secret entrance...

I'm using:
aspect_ratio=false
fullscreen=true
gfx_mode=advmame2x

Any help would be appreciated.

[Arisme]

I think that's beacause the filters and display in 640x480 mode are not well optimized.