Magicjack doesn't consider it a problem. They say the program was designed to work that way. MJ does not want the computer to be turned off because it will cut off their phone connection, end of discussion.
What happens is when you plug in their device to a USB port all the power control settings are useless so the screen saver never comes on, the computer will not sleep or hybernate. Unplug and everything is ok. I think they are issuing some sort of system overrides. I have been able to get my screen saver and light sleep mode working again using the "powercfg -requestsoverride" commands via the cmd window. I still can't get hybernation back. This is about the limit of my technical ability. I don't like tampering with system stuff.
It seems MJ could have written the software to maybe give you the choice of going to voicemail during hybernation or leaving the computer on 24/7.
The MJ device is an external device therefore portable. So I guess that brings on more issues.