For your CM11A interface device, is your serial port set correctly?
You should have options such as /dev/ttys0, /dev/ttys1, and if you have USB serial adapters, you should have also something like pci0000:00/0000.........
Make sure the correct one is selected.
Also while on this page, look at your controlled by field.. It should be an actual Core or MD device (mine is Core)
Now lets make sure your lights are correct webadmin->devices->Lights
1-Make sure the Controlled By field is set to CM11A
2-IN the Port/Address field is where to put the X10 House/Unit code in the format of A1,C2,D11, etc
Also, if you unplug your CM11A for 15 seconds from both the wall and the computer, it will reset the interface incase it is locked up