grid size not working?

[blinking halo]

hi,
im new to hammer, and i wanted to make the grid unit sizes smallers. theres an option under the 2d views tab on the options dialog which says grid size, and lets you pick all kind of powers of 2, but for some reason i cant understand, the grid size doesnt change when i set it.. i saved and closed my map and reopened it but the grid size stays at 64, which is a bit too inaccurate for the geometry im working on.. can someone plz tell me how to change the grid size, or is this feature just broken?
thanks for any replies
blinking halo

 

[Dux]

Go to map > grid settings. Or just press your bracket keys. []

 

[Ti133700N]

Make sure you have zoomed enough to see the difference between the 64 units grid and the smaller one. Otherwise the grid won't seem to change. Also, make sure "snap to grid" is activated.