I hope this is the right place to post this because I'm just really freaking out over my phone. So I have a 3gs with the old bootom and baseband thing. I wanted to upgrade it last night to 4.3.1. I looked up a couple guides and made sure I had everything right. First, I used redsn0w, but something went wrong, so I restored it. Then, I tried to use PwnageTool, but for some reason the ipsw file wouldn't open because of "wrong firmware bundle", even though I did everything in the directions. I was frustrated by now, so I decided to switch to my Windows computer and try out sn0wbreeze 2.4. Everything was going fine until I tried to update my phone to the customized ipsw. iTunes gave me an error of "Unable to restore (1600)" and another (1601) second time around. Now my phone is dead. It won't turn on no matter what I do. But iTunes still recognizes it when I plug it in. What does this mean? I hope someone can really help me out. I'm stressing like crazy over this.

There is no supported jailbreak for 4.3.1 yet. Sn0wbreeze doesn't work reliably, the jailbreak patches it applies are not stable or reliable. You should have waited until the dev-team or chronic dev released their jailbreak tools. We will not support Sn0wbreeze here because it's unreliable, unsafe, and in just about every instance causes more problems than it solves.

If you have an SHSH for 4.2.1, I recommend you restore back to 4.2.1 and use Pwnagetool to jailbreak. Aside from that, your only real choice is to wait patiently for a proper 4.3.1 jailbreak.

Seriously, we can't stress this enough. Sn0wbreeze is bad news. We don't even call it 'jailbreak' software anymore, we call it 'failbreak' software.

FYI, PwnageTool didn't work because it's not updated to support 4.3.1, and the only way to make it work is a backend hack that is also unsupported.

Thanks for the info! I wasnt aware of sn0wbreeze's unreliability/unstability. I guess I'll just update and wait.

There is a blanket policy here at hackint0sh to not support or recommend any tools from ih8sn0w (sn0wbreeze, iREB etc)

To put it in "celeb terms"
the iPhone dev team, geohot and chronic dev team are all A-list jailbreaks - these are generally well tested and contain the correct kernel patches to allow ALL Cydia tweaks to work properly (assuming the developer has bothered to test/update their tweak for the latest iOS version)
Sn0wbreeze sits somewhere between A-list and B-list
Everyone else is B-list or lower (including the 3rd party pwnagetool bundles to tethered jailbreak 4.3 and 4.3.1 that are promoted on sites like redmondpie). The developers of these jailbreaks often use semi-automated "fuzzy patchers" to port the jailbreak to a new iOS version. This can create undesirable results.

We only recommend and support A-List jailbreaks here. ih8sn0w has many valuable contributions to the jailbreaking scene but he can't match the gold standard that is required for A-list status.

Deveopers of tweaks sold via Cydia often refer to the jailbreaks created by B-list hackers as failbreaks. This is a very accurate description, we recommend that you take extreme caution if you want to use one of these failbreaks.