LinuxQuestions.org - QuickSynergy doesn't seem to execute

I have tried to follow the GUI portion of the instructions found here:

https://help.ubuntu.com/community/SynergyHowto

but cannot get the program to function (i.e. show me the client screen)

Just to ensure that I understand the instructions given in guide (they are a little hard to follow):

The controlling computer is known as the "Host", also the "Server", and is the computer with the mouse & keyboard.

On the "Clent" computer/s, which is/are to be controlled by the Host/Server computer, nothing is typed in the "Share" tab. In the "Use" tab, the IP# (alternatively, not in addition to, hostname with .local added to the hostname) of the Host/Server computer is entered in the box labeled "Server hostname/IP address". I have tried IP#, and hostname, with and without .local .

In the box labeled "Screen name:", enter the hostname of the Client computer (presumably without the .local as it is not mentioned in the instructions) [I have also tried it with the .local added] The name of my host computer has a space in the name (e.g. "my computer". Is that a problem?

On the Host machine, all IP#'s (or hostnames) of client computer/s is/are entered in the desired direction box of the "Share" tab, and no entries are made in the "Use" tab. (I am using IP #'s since there is no ambiguity, but have also tried the hostname of the client computer, with and without .local added to the hostname.)

When I click "Execute" everything goes grey (on both computers) on the setup box except the buttons at the bottom which now show as "About, "Stop" and "Close". I do not know whether QuickSynergy is attempting to communicate, but I assume that whatever is happening is incomplete because if I move my mouse to the appropriate edge of the screen, the screen does not change to the client computer.

I can ping each computer from the other, and reach each from the other at Places/Network so I assume that communication between the computers is not an issue.

I have not gone past the GUI portion because it quickly gets above my level of experience and understanding.

Can anyone see in the above anything that I might be doing wrong? Thanks.