Here are my pertinent stats first off:
1. Ubuntu 6.10 (Edgy)
2. Firefox 2
3. Java 1.6 (installed sun-java6-bin and sun-java6-jre packages from synaptic)
4. Radeon 9600
5. 512 MB RAM
6. 1.9 GHz CPU

I've been playing an online game (called PoxNora) for the past week and this game is started through Java Web Start from a link on the game's website. Now my problem is that if I start the game for the first time since my last reboot, it works flawlessly (JWS starts up, splash screen shows, app runs in its own window, all graphics are fine, etc.), but if for some reason the app closes (like I'm disconnected from the server or something) and I click to reopen it again, I see the JWS splash screen and then the app's window with a completely white background and then my entire computer locks up and the only thing that I can do is a hard reboot. After this reboot, the game works fine again, ONCE and the same problem inevitably occurs. I do use another web start program that works fine no matter how many times I run it, so it must be something specific to that game.

I've posted on the game's forum and I've even sent an email to their support address asking for any help, but I've received none. I'm not really asking for a solution here since I don't know if anyone here is familiar with the game or how it's run (though I'd be happy to have one), I'm just asking for help from someone more well-versed in java in diagnosing the problem (e.g. what log files or error reports should I look at?) since java on linux is proving rather complicated.

Any help would be greatly appreciated.

Thanks

you should look in /var/log to see whats going wrong

Can you tell me what files to look in and what I should be looking for? I'm unfamiliar with this directory and its contents.