+1 for that PSU is no good. If your looking for a cheap PSU the best cheap one to suit that system would be Antec Earthwatts 380w http://www.amazon.co.uk/Antec-EA-380GREEN-380W-EarthWatts-Green/dp/B002UOR17Y/ref=sr_1_2?ie=UTF8&s=computers&qid=1294192834&sr=1-2
. Although it states 380w vs your choice CIT 450w, the CIT is 450w MAX where as the antec is rated 380w CONTINUOUS. that CIT unit would not produce 380w continuous and is a low quality unit. If it doesnt blow up when you plug it in, it will blow up in 6 months time. Go with above suggestion of Antec, Seasonic or corsair.