Ok let me first start out by saying I had a Firmware 1.1.4 and it was buggy meaning my mail didn't work, YouTube, Stocks and it kept restarting when I push the sleep/wake button. It was just all messed up, below is a guide I made from my experinces with 1.1.4 and how to restore without getting "error" from iTunes or if you simply want to downgrade.

This is for Windows ONLY!!!

Thing you Need,
-Firmware 1.1.1

Step 1: If you are on this step you have firmware 1.1.4 and are getting an "error 1604" message on iTunes or whatever it is when u tried to restore, or if you simply want to downgrade your firmware. First put your iPhone in DFU mode.

Step 2: If you are on this step you have your iPhone in DFU mode and it is being reconized by iTunes. Next you want to hold "shift" and click restore and navigate to the fiirware 1.1.1 which you downloaded earlier. Now let iTunes do its thing and at the end you will get and "error" message.

Step 3: If you are on this step you have 1.1.1 firmware and are getting an "error" message from iTunes. Next open iBrickr and it should say begin downgrade to 1.0.2, click that option and let iBrickr do its thing. Once finished you should get a yellow triangle on your iPhone.

Step 4: If you are on this step you have downgraded to 1.0.2 on your iPhone with iBrickr and are getting a yellow triangle. Next iBrickr will ask you if you are getting a yellow traingle click "yes" and it will say "Fix it" click this and let it do its thing, after its done you will have a working 1.0.2 firware on your iPhone.

Step 5: If you are on this step you have firware 1.0.2 on your iPhone. Now you are free to upgrade to any firmware you want to. I updated mines to 1.1.4 through iTunes when it prompted me too. Also jailbreak 1.1.4 using ZiPhone 2.4 or lower, DO NOT use 2.5 or above because the Customize application does not work on 2.5 or higher.

If this guide helped you don't forget to click "Thanx" button