Timed Out (Failed to connect to server)

I was having the same problem, where I was able to get the client to connect initially, but then it just stopped working. It turns out that I had rebooted my host machine, which re-enabled the firewall. As soon as I disabled the firewall on the server, the client connected immediately.

Not being content with leaving my firewall off all the time on my Windows 7 machine, I added the server executable to the list of applications the firewall lets through and turned it back on. To do this (on Windows 7, at least):

1. Open Control PanelSystem and SecurityWindows Firewall.
2. On the left select "Allow a program or feature through Windows Firewall."
3. Click on the "Allow another program" button.
4. Even if Synergy is listed in the list of programs, don't select it. It's the wrong executable.
5. Instead, click on the Browse button, and navigate to C:Program FilesSynergy and select synergys.exe. Notice the 'S' on the end of the file name. That stands for Server, which is the executable that accepts incoming connections.
6. After adding that exe you should now have an entry for synergys.exe in your allowed applications list. Put a check in the "Home/Work (Private)" column next to this entry, and click OK. I did not put a check in the "Public" column because my computers are on the same network.

After hitting OK, my client connected immediately. I didn't even have to restart the client or the server. I hope this helps someone get connected. Synergy is a beautiful thing when it works!