Long cables for Gecko G340s

Turned out I needed longer cables for one of the axes of my flame
burning conversion and I am running into Tom Eldregdes problems as
covered in this and other posts.

http://groups.yahoo.com/group/CAD_CAM_EDM_DRO/message/27064

I am confused about what I need to get this running properly.

Can anyone summarize what is needed. The posts mention:
1. Ground the motor shield at the case.
2. Add a small capacitor to the encoder?
3. Don't ground the enconder shield?

Thanks in advance for any help.

Andy