This is the easy way to fix the signature failed crap on your vibrant. You should only have to this if you are running 2.2 or higher. I am unaware if it works for other galaxy s devices, I have a vibrant and it took around one minute to do. As always, use at you own risk.
You should have the drivers on you pc, also adb setup. Also you must have root, if you don’t have root, google “one click root for vibrant”. Root your junk and continue on.
1. Put your phone in usb debugging.
2. Plug your phone into your pc.
3. Download this 3e_recovery_installer
4. Unzip the thing
inside you will find a install batch file.
5. Run the install.bat file
6. Follow directions in the window that pops up
7. After it is done, unplug your junk and try to install clockwork recovery again. If it does not work the first initial time, just select reinstall packages on your phone. It normally takes 2 times to flash, and that’s it.
8. Put your rom an the INTERNAL SD.
9. Have fun.