ok...i previously had ios 3.1.3, jacked my phone all up playin with stuff i shouldnt have , restored and upgraded to ios 4.0. Do i need to just follow these steps or should i do something else??? any help would be greatly appriciated!!!!

Please don't threadjack. Post your own thread if your question isn't topical.

Without knowing what kind of phone you have, we can't really help.

If you have a 3G, you can still downgrade, jailbreak, etc. If you have a 3GS you'll need an SHSH to downgrade and jailbreak, and if you've got a new bootrom 3GS, you can't jailbreak 4.0 via any supported method at present.

Let us know the model, the bootrom, etc., and we can help, but until then it's just guesses.

3Gs w/ modem firmware 05.13.04, iOS 4.0, Model MC135LL

sorry for the thread jack...i'm also a complete newb to the iphone for the most part!!!!!!!

You'll want to find out what iBoot revision you have. Easiest way is to boot your phone into DFU mode (tutorial on iClarified if you're unsure how), open device manager, and go to the details for the USB device that registers when you plug in the iPhone. In the details view you'll end up seeing either "[iBoot-359.3]" or "[iBoot-359.3.2]". If you have 359.3, that is old bootrom. If you have 359.3.2, that is new bootrom.

That said, based on everything I've gathered so far, you're probably out of luck. From where you are, you'd need a 3.1.2 or 3.1.3 SHSH in order to downgrade to a firmware that is jailbreakable on your device, 4.0 is not jailbreakable while running on the 3GS, it must be flashed pre-jailbroken (make custom firmware with PwnageTool then apply to an already pwned+jailbroken phone). If you can't downgrade to 3.1.2 or 3.1.3 in order to jailbreak+pwn your device, you will be unable to jailbreak 4.0 at present.

I think your only option now is to wait until the new tools are released.

Good luck!