Ensure that you have the firewall exclusions set on the machine you are attempting to remote into, or stop the Windows Firewall Service first, just to test whether or not this is the problem. Also, check the event logs on the remote pc to see if it is even getting that far. There should be a couple of entries in the Application Log, one for LD Remote Control Service, and another for the Interactive Services.
Does the web remote control work on the same devices? http://LDServer/Remote