Yo dawg we heard you like computers, so we put a computer in your computer so you can use your computer while using a computer.
In seriousness, the ComputerCraft mod has been updated for compatibility with Minecraft 1.1. The new version, 1.21, also adds a shutdown keyboard shortcut. It also adds some more help features and includes several bug fixes. The update is now available to download at the source link below.
Source: Minecraft Forum