[U-Boot] Uboot-Mini2440 Not recognizing ARP replies

[Embedded User]

Hi

I am using a Mini2440 Board and using Uboot-1.3.2 on it. I am connecting it
to a my Host Machine which has Ubuntu 11.04 on it.
After downloading the Uboot image on the board, through USB, I am able to
boot up and set the environment variables like
ipaddr,serverip, netmask and ethaddr, to connect to my host machine.

Settings on mini2440 are -

setenv ipaddr 192.168.1.2
setenv serverip 192.168.1.4
setenv netmask 192.168.1.255
saveenv

The address of eth0 on my Ubuntu machine is 192.168.1.4. The host and
mini2440 are connected directly though a network cable.
The serial and USB interface of mini2440  are also connected to the same
host.
Now after setting the environment variables I try to do a TFTP from my
mini2440, then I see ARP requests being sent out, which are received by
the host and replied back( This I monitor using Wireshark) . But I dont see
any message being received back on Mini2440. I have enabled network level
debug prints and I am not able to see any packet receive print. I dont think
its a Physical layer issue as the ARP packets are transferred correctly.

I am missing out some configuration or some flag/switch during my build.

Regards & Thanks.