I'm running a stock 3GS. Yesterday, while texting, my phone suddenly lost signal and I got the message "core baseband dump.". I turned Airplane mode on and off, still couldn't get a signal and then a message appeared stating I needed to restore and that I could only make emergency calls. However, after a reboot, it worked fine again. I sarched around and found no clear explanation as to why this happens, but it's happened to quite a few people. Some were able to get it working after a reboot, some had to restore, and some were followed by "Repair Needed" prompting a trip to the Apple store. So, does anyone have any knowledge with regards to this issue? So far my phone is working fine but I'm concerned it might happen again, as it has with others.