Your Base Station may not be in the best location. One trick for finding the best location in your home for the base station is to put your system in "test mode" and then look at the brightness of the blue light at the bottom of the base station. The brighter the light, the stronger the wireless signal (this only works in test mode though). The signal strength indication will update about once every 15 seconds, so you can try putting the base station in a new location for 15 seconds and then see if the brightness increases. The location with the brightest blue light is best and is typically found within 3-5 feet of a window.

It does help to power reset the base station before troubleshooting the location:

Here are the instructions:
1) Remove the power plug from the back of the base station
2) Remove the batteries, you will need a screwdriver to open the battery chamber at the bottom of the base station
3) Replace the batteries
4) Plug in the unit and it will restart in test mode

You can now exit test mode by pressing 'Off' on the Keypad. When you find the location with the brightest blue light, retry your online command features.