Strange problem with OCZ Powerstream SLI 600W

[CubicleGeek]

I have a problem when I shut down the computer it won't turn back on the next time unless I also turn off the PSU. If I forget to turn off the PSU when I shut down, the next time I want to use the computer, I need to turn it off for a few minutes and flick it back on before the computer will respond to hitting the power button. Now, as I'm writing this message that trick doesn't seem to working at all now. I think my PSU is dead.

Any suggestions? How about similar experiences?