i have a 3gs that i was somehow i was able to upgrade to stock fw in itunes from 4.2 with ipad bb to 5.0.1 recently and then jailbreak with redsnow. if memory serves me, it even changed the baseband. but i have never heard of that happening, so i could very well be wrong. anyhow, the reason i did that was only because it was having intermittent "no signal" issues. i thought that maybe upgrading would help the issues. however, it continued to drop signal several times a day.
since it appears that i should have originally gone the custom fw route to begin with, and i had just created a custom fw with sn0wbreeze for another jailbreak i was doing (also a 3gs with ipad bb), i thought i'd install the custom fw and see if that solved it. i put it in dfu, hit shift restore in itunes and all went well until the phone wanted to reboot and now it is stuck in a dfu loop. i have tried tiny umbrella, recboot, and ireb. i also tried a tool i have called fix recovery. nothing worked.
can someone please help? this is my partner's phone, not mine and i am freaking out that i've bricked her phone!
i swear i am never jailbreaking another iphone again. as soon as i think i get the hang of it, some new error pops up and i'm stuck again!