you are fucked...
had the same problem with upgrading to 1.1.1 from 1.0.2 with 1.1.1 baseband. sorry to bring this to you, but the only way you can get this shit fixed is by trying various methods. if it makes you happy i got through this.. but that was after 10 hours of trying and failing every fucking time.

Somehow I got through it. I had tried Independence on mac, iBrickr, winstaller and all there is,
but it all ended up with "incorrect sim" however I
upgraded/downgraded... But then suddenly, after using iBrickr to
downgrade from 1.1.1 and still in "incorrect sim" mode in 1.0.2, I
installed apptapp, launched winstaller, and installed a couple of
progs (no matter which ones I suppose) in iBrickr, AND THEN LAUCHED
independence on a MAC i got it it to jailbreak and start up and view
springboard. I was so happy (and lucky i guess). So I found this one
guy on the internet who saved me with one amazing quote (because when
it was in this mode i also had f***** up IMEI which will happen to
everyone in this state...my guess.. it starts with 0049...something):
restart you iPhone without your SIM in and you will get your IMEI
back... did that and my beautiful IMEI was back on track.

Hi,
I had the "incorrect sim" with my iphone after i upgraded a f***** up baseband from 1.0.2 to 1.1.1 before virginizing. I struggled for 10 hours not being able to get any further with downgrading back to 1.0.2 or upgrading to 1.1.2 or whatever i did. There was people out there having the same problem, but no one answered to what they could do to fix it. Because when you have the "incorrect sim" message you pretty much are completely f*****. But somehow I got through it. I had tried Independence on mac, iBrickr, winstaller and all there is, but it all ended up with "incorrect sim" however I upgraded/downgraded... But then suddenly, after using iBrickr to downgrade from 1.1.1 and still in "incorrect sim" mode in 1.0.2, I installed apptapp, launched winstaller, and installed a couple of progs (no matter what I suppose) in iBrickr, AND THEN LAUCHED independence on a MAC i got it it to jailbreak and start up and view springboard. I was so happy (and lucky i guess). So I found this one guy on the internet who saved me with one amazing quote (because when it was in this mode i also had f***** up IMEI which will happen to everyone in this state...my guess.. it starts with 0049...something): restart you iPhone without your SIM in and you will get your IMEI back... did that and my beautiful IMEI was back on track. This is probably how far you guys want to know.. or dont want to know..depends.. but then installed mobileterminal and did all the stuff for downgrading baseband and I was on track to upload to 1.1.1 after 10 fu**ing hours messing around. Totally worked.

On the other hand now I have upgraded to 1.1.3 and I am one of those "new themes and display every day" kind of guy so the fact that customize and summerboard doesnt work on this firmware is a hazzle for me right now. Used iSwitcher, but to be honest, those themes f***ing su**s ba**s if you ask me. 1.1.3 su**s ba**s and everything about apple's new firmware su**s ba**s right now. APPLE STEALS THE IDEAS FROM THE APPS FROM INSTALLER and then makes "THEIR OWN" upgrades and puts them in 1.1.3. WHY NOT COOPERATE WITH SOME OF THE FANTASTIC PEOPLE THAT SPENDS TIME CREATING THESE AMAZING APPS THAT WE BENEFIT SO MUCH FROM AND MAKE THE IPHONE UNBEATABLE IN THE MARKET FOr NOW?

THAT PISSES ME OFF! sorry about the language, but it has got to be said. they steal the ideas and then block the programs that already had those ideas 4 months ago from being used in 1.1.3. makes sense? From apple's point of view...MAYBE.. from my point of view.. F*** U APPLE! LI** MY BA**S!

Sincerly,
Thomas