Going on now brb
ICS Droid Bionic
.246 courtesy of HoB
Put your phone in AP Fastboot mode manually.
Use the install 247 option.
Select N at the transfer step, md5 step, and AP Fastboot reboot step
Select Y at the RSD step
That will put you on stock 247 which is where I feel everyone 235+ should be at this point anyway. From there you can decide if you wanna play with CM10 again. I know one of my users has it working on 247 in safestrap so it can be done. Read the OP and my faq before you attempt it. But the INSTALL 247 option should work.
HOWEVER, that assumes one major point. Can you put something on the sdcard-ext manually without using the phone? Meaning do you have an sdcard reader or other phone you can use to copy a file to your sdcard? If you can't, we'll have to find you another solution that involves fixing 242 first. Let me know how you want to proceed.
EDIT: What I'm referring to is the 247 update zip. It needs to be copied manually to your sdcard-ext cause you can't boot.