Can't ping my default gateway - help

[Bullit]

Hi there,
hope you are all well this christmas season

I am running a home network with 3 computers and one router.
2 computers use XP home and one uses XP pro.
A xp home computer connects to the net and shares this connection successfully with the other two computers.

Now for the weird bit:
how come I can use the internet connection handed out by 192.168.0.1 (deflt g'way) yet I can't ping 192.168.0.1??
I'm trying to ping from my XP pro machine.
I can ping it from the other xp home machine

The problem is I cant ping the deflt gateway and also can't access any shared folders on it. It's the shared folder access that I really need.

Do you have any ideas?

-firewall on the xp deflt gateway keeping me out?
-something I need to change on the xp pro machine?

It's really odd - I get shared interenet but cant ping or see shared folders. Machine #2 can however

look forward to sorting this out! ;-)