Can not ping but can browse internet

Hi,

I have windows XP professional. I am using dial-up modem to connect to the internet. I have a NIC which is connected to hub. I connect to internet allright and I can browse the websites as well. But, on the same machine i am not able to ping the websites. I get “request time out”. Though the name resolution works fine. But I am able to ping my self (127.0.0.1) and dynamic ip address which is assigned to me by the ISP.
I have also tried by making internet connection sharing(ICS), but ping didn’t work.
Any help would be much appreciated.

Cheers!
Sameer