(OT) only 4 Viz users

[zeronove]

already posted in autodesk usergroup with no answer, so I'm trying here

anyone that is able to use the following option?

grid and snap settings/home grid/grid dimensions/perspective grid extent

on my VIZ 2005 doesn't work!
so I'm not able to reduce the dimensions of my home grid like in Max; it always fades to horizon overloading the video card without any sense!

Is it a bug or is there any solution?

please help
thx
a.