My friend has a network between his and his mothers computer using a crossover cable..., but it suddenly stoped working..

First step to fixing any network is pinging the other's IP address...

1/2 to 3/4 of the pings timeout, but the other ones have a ping under 1 ms..., my first thought was it could be something up with the cable, so I tried hooking up the laptop using the same cable...

the network worked prefectly in place as my friends computer (so , the laptop was networked with his mothers) but when it was in place as his mothers computer, it acted just as before..., meaning the problem must be at my friends end?...

I have never encountered something like this before...

what do you guys think?

thanx in advanced,
Byan