mine says it will absoluetly not work with a power supply under 350W, but it does. this power supply is amazing. I know its hard to believe but i have never had one problem with shortage of power and i just got anothe 160 Gig harddrive. I didnt believe it at first either but it really is not a problem.
go to
http://forums.sudhian.com/categories.cfm?catid=43&FTVAR_SUBCAT=68&subcatname=SFF%20TECH if you dont believe me. Its the small form factor official message board i believe. They are seriously getting tired of hearing people ask about the small powersupply though. There are some people there who have 3.0c Ghz processors, with FX5900 Ultras, 2 Gigs of Ram and 2 giant harddrives and the pci slot taken up and they have not had any problems. Believe me. nVidia has put together some gaming systems itself in the shuttles and they use the tiny PSU's. Its not a problem.
I have however had one problem, it gets hot in that tiny box. So i put a blowhole on the top of my case with an 80mm fan and everything runs perfect now.