Using Modeline In XFree86 4.0.2 Config file

[Mikenell]

When I start my computer my linux screen is always in the wrong position, in XFree86 3.3.6 I fixed this by changing the the screen with xvidtune and then added what it showed in the XF86Config file with Modeline before it, but it doesnt work the same way with XF86Config in 4.0.2, what can I do now to make it be in the right position?
Thanks
Mikenell