I've got the same PSU and it's been running my overclocked i5 750 and overclocked 5850 in crossfire without fail.
So keep that in mind, if you already have that PSU, just keep it. It's not a great PSU but it does the job. Keep in mind that the reviews of most PSU's are done with North American standard of electricity, which is 110 Volt, if you power your PSU with 220-230 volt, it's run around 4% more efficiently, plus run generally better cause of the better amperage.
So if you don't have a PSU and you're buying a new PSU, best buy another one, but if you get it for a sweet deal as I did (around $78) it's no harm using it since by the time the ripples will tire your capacitors you would have already moved on to the next greatest motherboard and GPU's.
If you're keeping your system for over 3-4 years then probably get another PSU if not, just keep it, its here, its free, and it'll run your system until your next rebuild.
Here's my build with that PSU and overclocked crossfired 5850's. And it hasn't shut off once due to the PSU.
if you do crossfire your 5850, be sure to download "RadeonPro" it's free and its the best program to use with crossfire, you can set profiles with different drivers for different games on the fly, awesome.