Native X Server ignore vnc Options

[info]

Hi, is there anyone telling me where's my fault ?

I  can't understand why the X server ignores the vnc options
inserted in xorg.conf; /var/log/Xorg.0.log states :

(WW) I810(0): Option "SecurityTypes" is not used
(WW) I810(0): Option "localhost" is not used

I'm trying to use vnc through a ssh tunnel in fedora 3 with
kernel-smp-2.6.11 & last Xorg distribution.

Thanks in advance

Lucio

Here is my xorg.conf 

Section "ServerLayout"
	Identifier     "single head configuration"
	Screen      0  "Screen0" 0 0
	InputDevice    "Mouse0" "CorePointer"
	InputDevice    "Keyboard0" "CoreKeyboard"
EndSection

Section "Files"
	RgbPath      "/usr/X11R6/lib/X11/rgb"
	FontPath     "unix/:7100"
EndSection

Section "Module"
	Load  "dbe"
	Load  "extmod"
	Load  "fbdevhw"
	Load  "glx"
	Load  "record"
	Load  "freetype"
	Load  "type1"
	Load  "vnc"
	Load  "dri"
EndSection

Section "InputDevice"
	Identifier  "Keyboard0"
	Driver      "kbd"
	Option	    "XkbModel" "pc105"
	Option	    "XkbLayout" "it"
EndSection

Section "InputDevice"
	Identifier  "Mouse0"
	Driver      "mouse"
	Option	    "Protocol" "IMPS/2"
	Option	    "Device" "/dev/input/mice"
	Option	    "ZAxisMapping" "4 5"
	Option	    "Emulate3Buttons" "yes"
EndSection

Section "Monitor"
	Identifier   "Monitor0"
	VendorName   "Monitor Vendor"
	ModelName    "Acer AL1921"
	DisplaySize  380	300
	HorizSync    30.0 - 83.0
	VertRefresh  55.0 - 75.0
	Option	    "dpms"
EndSection

Section "Device"
	Identifier  "Videocard0"
	Driver      "i810"
	VendorName  "Videocard vendor"
	BoardName   "Intel 865"
EndSection

Section "Screen"
	Identifier "Screen0"
	Device     "Videocard0"
	Monitor    "Monitor0"
	DefaultDepth     24
	SubSection "Display"
		Viewport   0 0
		Depth     16
		Modes    "800x600" "640x480"
	EndSubSection
	SubSection "Display"
		Viewport   0 0
		Depth     24
		Modes    "1280x1024" "1280x960" "1152x864" "1024x768" "800x600" "640x480"
	EndSubSection
	Option "SecurityTypes" "None"
	Option "localhost"
EndSection

Section "DRI"
	Group        0
	Mode         0666
EndSection