BleepingComputer.com: Cain Error

Whenever I start using Cain, it gives me an error - "Error : PacketReceivePacket failed"
My computer is hp laptop, windows xp sp2..... i disable my antivirus - avast home edition 4.8 whenever i run this cain.exe, but still i get this error...i have installed winpcap 4.0.2 and wireshark 1.0.5
Wireshark is able to capture the packets, but then i dont know wat to do with them.....
we have our network with the http proxy 8000.......
please help me out....
waiting for your reply.....