Glitch or genuine disconnect?

[GeniX]

After my first attempt at multiplayer civ3 saw the game get a synch error shortly after start, I joined another.

The next one went well - was playing for an hour at least. Then one guy unexpectedly leaves the game. A turn later, the other guy also leaves (leaving me playing two AI's - I wasnt the host, btw).

Ofcourse I assume they decided to quit, but when I get back to Gamespy chat, it seems quite sure that those users are both still in a game. So either gamespy's player list is lagging and not up to date, or it was my machine on which the error occured.

Can anyone shed any light? I'm keen to find out when these things are my machines fault so I can try trouble shoot. While PTW may have issues in it, theres bound to be a better or more stable system config for it.