I have Vista ultimate with SP1 installed. I have installed Nimo Codec Pack.
I've had that installed before with no problems. I had issues with Vista SP1...which caused me to format etc so maybe that ridiculous "update" has something to do with it as well.
I am starting to suspect my PSU a little more as I have experimenting with things like unplugging or plugging in any extra stuff (webcam, mp3 player etc.) and it seems that when more is plugged in I have more problems. I think a webcam, Logitech G15 Keyboard, mouse with LEDs, and so on draws just enough power together to tip the scale. The fan might not spin quite as fast as it should and cause a heat problem as well. I am thinking that a 500 or 550 watt PSU might not be a bad idea at this point.