ad-hoc problem

[manishas at cdacindia.com]

hello,
    thanks for the help to work out ad-hoc mode.

i have run following commands on two laptops

 machine 1:
           iwconfig wlan0 essid test-adhoc
           iwconfig wlan0 mode ad-hoc
           iwconfig wlan0 channel 3
           ifconfig wlan0 192.168.6.x


 machine 2:having hostap driver
           iwconfig wlan0 essid test-adhoc
           iwconfig wlan0 mode ad-hoc
           iwconfig wlan0 channel 3
           ifconfig wlan0 192.168.6.x

and i am able to telnet through each other.
the problem was the machines are not on same channel

the ad-hoc network is of more than two wireless machines,isn't it?so why i 
am not able to communicate using three machines?

       with above working condition,i configure my another machine for ad-
hoc network.but this time machine has winxp operating system.i have 
configured winxp's wireless connection to act in ad-hoc mode.the status 
shows that it is associted with first machine as shown in status window
(associted with).

         i am also able to ping first machine and machine having winxp.
but winxp and second machine are not able to communicate with each other
(i.e. no positive ping reply from each other)

          what is the problem?

what is the significance of the cell address in iwconfig stastics?

thanks in advance

with regards,
manisha