halo:combat evolved freezes

well when my grandpa starts up halo , and goes to the internet lobby and hits refresh, this is when it freezes. After waiting for a while it will say gamespy has an issue, but it does not, because i am playing it on my mac at the same time he is trying to connect , but me without any problems. whats the issue? please help, thanks.

sorry for the horrible "paragraph", im on the phone ATM.

What kind of computer is he using, what OS, and what version of the game?

Mac [newest model]...Os X Tiger, and the trial version of the game.

oh and this just started happening, he could play w/ out any problems before.

Can you find out what changed between the time the game worked well and when it started bugging out? Did he install a new app? Did he update an app or the OS? Did he add a peripheral? Did he change anything in his user account?

What he could try is create a new user account with the same level of privileges and see if the game plays well in the new account.