How to use networkmanager-applet to creat wireless internet sharing?

Question

hi,
I'm trying to creat a wireless connection to share internet with another laptop.
I followed the usual step like how i did it on Ubuntu
Creat New Wireless Connection-->
then I setup a connection
Mode: Ad-hoc  (No security password, cuz it's for testing)
ipv4 settings: Method: shared to other computers
when I tried to connect to this connection, it does work for only a second. the notify-osd says connection established, then changed into disconnected right after. and the connection does was detected on the other laptop (with vista), but only last about a second.
I have no idea what happed. but it works perfectly on Ubuntu, with the same operations.
also, if I create a connection on vista, it can connect to that connection.
what should I do to make it works as well as how it does in unbuntu?
# /etc/rc.conf - Main Configuration for Arch Linux
# LOCALIZATION
# LOCALE: available languages can be listed with the 'locale -a' command
# HARDWARECLOCK: set to "UTC" or "localtime"
# USEDIRECTISA: use direct I/O requests instead of /dev/rtc for hwclock
# TIMEZONE: timezones are found in /usr/share/zoneinfo
# KEYMAP: keymaps are found in /usr/share/kbd/keymaps
# CONSOLEFONT: found in /usr/share/kbd/consolefonts (only needed for non-US)
# CONSOLEMAP: found in /usr/share/kbd/consoletrans
# USECOLOR: use ANSI color sequences in startup messages
LOCALE="en_US.utf8"
HARDWARECLOCK="localtime"
USEDIRECTISA="no"
TIMEZONE="Asia/Shanghai"
KEYMAP="us"
CONSOLEFONT=
CONSOLEMAP=
USECOLOR="yes"
# HARDWARE
# MOD_AUTOLOAD: Allow autoloading of modules at boot and when needed
# MOD_BLACKLIST: Prevent udev from loading these modules
# MODULES: Modules to load at boot-up. Prefix with a ! to blacklist.
# NOTE: Use of 'MOD_BLACKLIST' is deprecated. Please use ! in the MODULES array.
MOD_AUTOLOAD="yes"
#MOD_BLACKLIST=() #deprecated
MODULES=(acpi_cpufreq cpufreq_ondemand cpufreq_powersave usblp usbcore)
# Scan for LVM volume groups at startup, required if you use LVM
USELVM="no"
# NETWORKING
# HOSTNAME: Hostname of machine. Should also be put in /etc/hosts
HOSTNAME="kwan-laptop"
# Use 'ifconfig -a' or 'ls /sys/class/net/' to see all available interfaces.
# Interfaces to start at boot-up (in this order)
# Declare each interface then list in INTERFACES
# - prefix an entry in INTERFACES with a ! to disable it
# - no hyphens in your interface names - Bash doesn't like it
# DHCP: Set your interface to "dhcp" (eth0="dhcp")
# Wireless: See network profiles below
#Static IP example
#eth0="eth0 192.168.0.2 netmask 255.255.255.0 broadcast 192.168.0.255"
eth0="dhcp"
INTERFACES=(lo !eth0 !ath0)
# Routes to start at boot-up (in this order)
# Declare each route then list in ROUTES
# - prefix an entry in ROUTES with a ! to disable it
gateway="default gw 192.168.0.1"
ROUTES=(!gateway)
# Enable these network profiles at boot-up. These are only useful
# if you happen to need multiple network configurations (ie, laptop users)
# - set to 'menu' to present a menu during boot-up (dialog package required)
# - prefix an entry with a ! to disable it
# Network profiles are found in /etc/network.d
# This now requires the netcfg package
#NETWORKS=(main)
# DAEMONS
# Daemons to start at boot-up (in this order)
# - prefix a daemon with a ! to disable it
# - prefix a daemon with a @ to start it up in the background
DAEMONS=(syslog-ng hal fam cpufreq @laptop-mode ufw networkmanager dnsmasq netfs cups crond avahi-daemon !network !lastfmsubmitd !lastmp alsa gdm)
[kwan@kwan-laptop ~]$ ifconfig
eth0 Link encap:Ethernet HWaddr 00:13:A9:50:3D:2B
inet addr:192.168.1.101 Bcast:192.168.1.255 Mask:255.255.255.0
inet6 addr: fe80::213:a9ff:fe50:3d2b/64 Scope:Link
UP BROADCAST RUNNING MULTICAST MTU:1500 Metric:1
RX packets:1628 errors:0 dropped:0 overruns:0 frame:0
TX packets:1788 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:1061372 (1.0 Mb) TX bytes:276083 (269.6 Kb)
Interrupt:16
lo Link encap:Local Loopback
inet addr:127.0.0.1 Mask:255.0.0.0
inet6 addr: ::1/128 Scope:Host
UP LOOPBACK RUNNING MTU:16436 Metric:1
RX packets:694 errors:0 dropped:0 overruns:0 frame:0
TX packets:694 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:0
RX bytes:34780 (33.9 Kb) TX bytes:34780 (33.9 Kb)
wlan0 Link encap:Ethernet HWaddr 00:19:7D:C0:F8:5A
inet6 addr: fe80::219:7dff:fec0:f85a/64 Scope:Link
UP BROADCAST MULTICAST MTU:1500 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:90 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:20024 (19.5 Kb)
wmaster0 Link encap:UNSPEC HWaddr 00-19-7D-C0-F8-5A-00-00-00-00-00-00-00-00-00-00
UP RUNNING MTU:0 Metric:1
RX packets:0 errors:0 dropped:0 overruns:0 frame:0
TX packets:0 errors:0 dropped:0 overruns:0 carrier:0
collisions:0 txqueuelen:1000
RX bytes:0 (0.0 b) TX bytes:0 (0.0 b)

Answer 1

I can't get this to work either.  I've tried everything I can think of.
Relevant configuration file:
# DHCP configuration generated by Firestarter
ddns-update-style interim;
ignore client-updates;
subnet 192.168.1.0 netmask 255.255.255.0 {
    option routers 192.168.1.1;
    option subnet-mask 255.255.255.0;
    option domain-name-servers 128.253.180.2, 132.236.58.250;
    option ip-forwarding off;
    range dynamic-bootp 192.168.1.100 192.168.1.110;
    default-lease-time 21600;
    max-lease-time 43200;
dnsmasq is installed and running.
created ad-hoc network in nm-applet, tried all sorts of different configs in there to no avail.
Has anyone gotten this working in Arch?