Here is a fix for Link Farm Evolution that replaces their captcha system with decaptcher.com's
Just get the file:
Then do this:
1. Edit the new file adding your decaptcher username and password
2. Save it
3. Open your LFE Installation, navigate to /includes
4. Make a BACKUP of captchaCracker.inc.php
5. Replace includes/captchaCracker.inc.php with this new file.