Comment 9 for bug 495916

Just to confirm Dale's observations - I've seen this behavior on my machine (System 76 PanP5) also only during VirtualBox sessions (guest = Windows XP Pro). It occurs with both my custom kernel (where I first suspected the problem might be) and on the current "stock" Ubuntu 9.10 kernel. Unlike Dale, it only happens occasionally and only with a guest session running, so I've had no reason to rmmod the vbox kernel modules. Interestingly, I've only seen this behavior when I have an external monitor connected -- typically, I'll have the guest OS running full-screen on the external monitor with my normal gnome desktop on the laptop monitor. This leads me to suspect a problem in xorg or the Nvidia driver (version 190.42) -- granted, this is the conclusion of an untrained eye.

I can attempt to reproduce the problem either tomorrow or Saturday (in the meanwhile, this is a "production" machine, so I need to get work done). Exactly what procedures should I follow for the purpose of collecting useful information? Usually, I get an "Apport" icon telling me there was a serious Kernel crash, but then it is unable to generate a report because i'm not using an "official" Ubuntu kernel. I'll remove my custom kernel before testing to prevent this problem and hopefully get something useful. Is there anything else I should watch for?