Disable Shadow?

[xy-maps]

Hello,

In the option menu is the point "disable shadow", I activated this point because "The Legend of Zelda Windwaker" lagged very in Levels with shadow.

But the Shadows didnt disapper...

Is this a bug or normal?

Are there Tweaks to let the shadows disapper?

specs:
Intel Core2Quad 4x2,5 Ghz
Nvidea Geforce 1048mb VRAM
4GB Ram
Windows 7