Ping and LAN Problem

[das দাশ]

Hello Friends:

I have two Ethernet cards, named by OS as eth0 and eth2. My DSL router
modem is connected on eth2. It is working fine (that is how I am sending
this mail :)). But, my laptop (on Ubuntu 7.04 too) connected to this
machine on eth0 of the desktop. The eth0 is fixed IP: 192.168.0.1 and
the laptop is 192.168.0.2. Earlier, I have always connected like this,
with ipmasq on in the Desktop. But, for quite some time, I did not use
the laptop. Now, when I am going to connect, the Desktop is giving a
queer message:

<<<
dd at mahammad:~$ ping 192.168.0.2
PING 192.168.0.2 (192.168.0.2) 56(84) bytes of data.
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted
ping: sendmsg: Operation not permitted

--- 192.168.0.2 ping statistics ---
4 packets transmitted, 0 received, 100% packet loss, time 2999ms
>>>

>From the laptop too, the ping is not working. It is getting stuck
without any output till I press 'Ctrl-c', though the self-ping with
'ping 192.168.0.2' from the laptop is working fine. 

Why this is happening? Earlier I have done all my works through this
LAN. And I know so little of this networking things. 

I am quoting the output of the 'ifconfig -a' on the desktop:

<<<
dd at mahammad:~$ ifconfig -a
eth0      Link encap:Ethernet  HWaddr 00:A1:B0:09:0C:8F  
          inet addr:192.168.0.1  Bcast:192.168.1.255  Mask:255.255.255.0
          inet6 addr: fe80::2a1:b0ff:fe09:c8f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:748 errors:0 dropped:0 overruns:0 frame:0
          TX packets:52 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:65766 (64.2 KiB)  TX bytes:3228 (3.1 KiB)
          Interrupt:17 Base address:0x4e00 

eth2      Link encap:Ethernet  HWaddr 00:E0:7D:89:F6:2F  
          inet addr:192.168.1.40  Bcast:192.168.1.255
Mask:255.255.255.0
          inet6 addr: fe80::2e0:7dff:fe89:f62f/64 Scope:Link
          UP BROADCAST RUNNING MULTICAST  MTU:1500  Metric:1
          RX packets:16925 errors:0 dropped:0 overruns:0 frame:0
          TX packets:27249 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:1000 
          RX bytes:3351843 (3.1 MiB)  TX bytes:21357939 (20.3 MiB)
          Interrupt:16 Base address:0x2f00 

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:24 errors:0 dropped:0 overruns:0 frame:0
          TX packets:24 errors:0 dropped:0 overruns:0 carrier:0
          collisions:0 txqueuelen:0 
          RX bytes:1408 (1.3 KiB)  TX bytes:1408 (1.3 KiB)

>>>

Very Bewildered-ly
das