I would say your putting a great strain on a 115W power supply with all those components, especially at poweron..
If you want to save electricity, turn your fridge down a notch, or change all your 100W lightbulbs to 60 or 75W .. Or better yet, change them to the long lasting, low power flourescent kind..
The 115W your saving isn't really that significant, and it's not like it's drawing the whole 230W constantly.
I was going to say, I've never heard of a power supply where you could adjust the wattage.. If you are indeed flipping that little 115/220V switch in the back, for god's sake, leave it at 115V if you live in the US!
I'm surprised it would even work while set to 220, If it even does..