- Turn SSH and Wi-Fi on in your iPhone/iPod.
- Open the SSH program of your choice on your computer.
- Goto folder /var/lib/apt/lists.
- Delete all of the files except for the partial folder AFTER backing them up.
- Disconnect the SSH connection in your program.
- Re-open Cydia.
If that fails then try method 2.
- Shell access (terminal or ssh)
- Type "Su" and your password.
- Navigate to the root directory and type the following.
- dpkg -configure -a
- apt-get update
- apt-get install cydia (if it fails add –fix-missing)
- apt-get upgrade (to install mobilesubstrate correctly)
DISCLAIMER - Beware when doing anything to your iPhone/iPod, make sure you back it up and it's all at YOUR OWN RISK!!!