Has anyone else had any problems with this pulse gen, in that if it sits for awhile, front keyboard commands are sluggish to work. (From the time you press the button, until the function takes place) could be 5 sec. to a couple minutes. This is happening with a couple of the 81150A units we have, in manual mode. Also, we have lockups in remote mode after the unit sits for awhile and the only way to reset it is to remove power with the electrical cord. Help!!