1. try restoring back to 1.1.2 den downgrade back to 1.1.1 using recovery mode... it will giv you "error 1015" so juz use independence for mac or ibrckr for windows to kick it off recovery mode...
2. you'll be at the activation screnn den juz dial *#307# den call it will ring... dn delete n dial 0 and it will ring again with "1" trying to call you... answer, put it on hold, unhold it and den decline the call... this will bring you to the MobilePhone app...
3. create a new contact and make 2 url's for the contact respectively "prefs://" & "jailbreakme.com" both without quotations... den save the contact...
4. tap prefs:// and it will bring you to your settings... connect to a wifi hotspot and go to general and set autolock to never.... press the home button and this bring back to the activation screen... juz dial 0 and again do wat u did b4 to go to the MobilePhone app...
5. Now tap jailbreakme.com and use appsnapp to jailbreak your phone... the phone will lock up and should reboot after its done and now you have jailbroken 1.1.1 phone... first add "hackthatphone.com/1.xml" on to ur sources for installer...
6. Install BSD Subsystem and den go to the Hack That Phone Tools den install "anySim 1.2.1u"...
7. Put in the sim card that you are gonna use for the phone then launch anysim... follow the instructions and if it goes smoothly u now hav a 1.1.1 unlocked again with 1.1.2 baseband... uninstall any sim then install OKtoprep and UPDATE to 1.1.2...
9. Once its done updating... you can jailbreak the phone again... you can find the jailbreak in this link
http://conceitedsoftware.com/iphone/site/112jb.html
10. juz double click on windows.bat if your on windows or on jailbreak.jar if on a mac... it will launch the app, close itunes and click jailbreak...
11. it shud be done in around 5 mins. and it will reboot by itself... if you find your phone getting stuck on recovery mode juz close itunes and use either independence or ibricker again...
12. now you have a jailbroken/unlocked 1.1.2 phone... juz follow the steps/instructions for the 1.1.3 upgrade and your all set...
Hope this helps you with your problem...^_^