[TxMt] Can't install Edit in Textmate package

I have just tried to install the "Edit in Textmate" package.

When I tried and failed, I got an error message which reads:

sh: tail: command not found

Error

The input manager (/Contents/Resources/Edit in Textmate) was not found in the Textmate application bundle.

You may need a newer version of Textmate.

I don't understand why this happens; I have just downloaded and paid for Textmate recently.

I'm also having trouble setting up the terminal command so that I can open Textmate using the "mate" command; the default links do not show up in the Enhanced Terminal Usage wizard box. If I were to navigate to the /usr/bin directory, which directories should I link to in order to set it up?

Thanks in advance.