The problem might possibly be caused by the animations plugin as you have observed, since I'm doing stuff (that might be going into some very rare infinite loop) while handling the ConfigureNotify X event, which gets fired on every mouse click. But why this would only happen on this specific group of hardware and only with the open source ati driver, I'll never know (it works fine with fglrx, which was the driver I was using all along). I'll do some debugging to pin down the bug (if it's in my plugin). Luckily I'm on a Mobility X300, and I can observe the freeze.
The problem might possibly be caused by the animations plugin as you have observed, since I'm doing stuff (that might be going into some very rare infinite loop) while handling the ConfigureNotify X event, which gets fired on every mouse click. But why this would only happen on this specific group of hardware and only with the open source ati driver, I'll never know (it works fine with fglrx, which was the driver I was using all along). I'll do some debugging to pin down the bug (if it's in my plugin). Luckily I'm on a Mobility X300, and I can observe the freeze.