For sure---it's really frustrating---but not only for the customer---but for us. I'm going to be putting "chokes" or"loop current regulators" on the lines that I'm having trouble with. This may be my last option. I've replaced everything except the phones themselves. This has been going on for 4 months. we replaced the whole KSU about two weeks ago---it was fine for about a week--then the VM started locking up again. It happens in the morning between 9:30-10:00 and then again between 1:30-2:00 in the afternoon. The only suggestion I can make is for you to keep eliminating hardware or ports, or lines, programming "glitches"
and eventually it will come to one area. If I find any kind of solution I will post it on this site.

Rockford VoIP