The first time Wii2600 is started it attempts to determine whether your Wii is running in PAL (50hz) or NTSC/PAL60 (60hz) mode. Based on this determination it sets a default value for Vertical Sync.
NTSC/PAL60
If Wii2600 determines you are in NTSC/PAL60 mode (60hz) it enables Vertical Sync by default. This should work well for both NTSC and PAL games. PAL games run fine due to the fact that they run at a slower rate than NTSC.
Full details http://wiibrew.org/wiki/Wii2600
