20 Sep 2007 at 18:51 - 8
Oh it happens at times... I've got it a few times, and so did some of my friends. I think data eventually gets corrupted by some mean or other (no idea WHY it happened to me, never really bothered to check why actually, but it happens). One of my buddies crashed the other night and took about 20 minutes to repair the archive. He played fine, with minor lag, when he loaded the map.
GW isn't the only program that can "corrupted" like this; sometimes this corruption appears to be a conflict with another program or application you are running, sometimes due to an unknown third-party program; heck even an anti-virus will, at times, say that such file is corrupted and will delete it... then it happens to be a driver that you need to run a program or a component. (I've never seen it applied to GW, 'cause the GW.dat file is one big file... doubt it's caused by an antivirus in this case).
TBH I'm kinda surprised that you got this for the very first time after 27 months. I think I've had it within the first month or so, so... 25 months ago x].