So I screwed up yesterday updating my iphone 3gs and now have version 5.0.1 on baseband 05.16.05. Since this is an extra phone, I have no problems updating to baseband 6.15.00. However, when I try doing this, my modem firmware doesn't seem to change. Can anyone help me in trying to update the baseband to 6.15.00, then to an untethered custom ipsw (4.2 or later?). I have tried a few times on my own by using google and am getting nowhere. I appreciate any help. FYI, i used redsn0w_win_0.9.6b6. When it asks for current software, I used iPhone2,1_4.2.1_8C148a_Restore and it proceeded. I am not sure if I am entering the right answer in regards to new/old bootrom (I clicked new) and also not sure if I should check/uncheck "install cydia" when I check "install ipad baseband". At the end, it notified me that I had a tethered software version (which I am trying to avoid). After I went through this process, I went to Cydia>Manage>Sources>Edit>Add>http://repo666.ultrasn0w.com. After that completed, one error message popped up halfway through, otherwise it completed just fine. Rebooted, no change to firmware version, no service (I am on T-Mobile).