It would depend on what all else that you had attached to it. The 250 should run with what you have listed.
But you got me on this ATX1 and ATX2 plug you mentioned.
>edit< I looked up your manual and took a look and see what you are talking about on the ATX1/ATX2..It is the pentium 4 pin plug,
Replace the power supply and try it that way before sending it back.