Mine has always worked well, except for my stupidity in testing it when my cell phone was turned off.

I thought it was the program, but I discovered when I tested it to see if when it rang, could it be answered from the main number when the cell was off, I only tried it by calling from the cloned line to the main line and under that scenario, it worked.

Otherwise, as a number of you indicated, when the cell is off, it immediately goes to its VM before any other intervention is possible....