Strange issue with device or pfsense not sure

[kalu]

Hello friends good day
I'm having bad day with Netgate m1n1wall which had pfsense 1.2.3
i upgraded it pfsense 2.0 RC1. I had not touched the firewall part.
Just configured the WAN /LAN Interface and the DHCP Server.
all of a sudden i couldn't ping the LAN interface of the router neither can i access webgui.
but for you kind information the client will get IP from DHCP server.
i unplugged the device connected it to desktop. To my surprise i can ping access webgui everything i need to configure the device.
does that mean my laptop's NIC has been damaged :p (but it still gets the ip from dhcp server)
or pfsense locks out unwanted clients after 3 unsuccessfull logins based on their MAC.

any guidance, suggestions and informations regarding this issue is appreciated
thanks in advance
kalu