I was having problems with the MagicJack making crackling noises when I was making or receiving calls. It was also not displaying caller ID data. I contacted support chat. They said to remove it from the dongle that was included with the MagicJack. Once I removed that it would not fit in the USB port I was using. They suggest that I plug it into the back on my machine when it would fit without the dongle. When I did that the crackle went away and phone numbers were showed on my caller ID. They also suggest I use a power USB hub. When I had I previous contacted support a couple of years ago they had told me to never use a hub because it caused latency or something like that.
The reason they gave me this time for needing to use a powered USB hub was that the crackle and caller being missing were being caused by a low power issue. The dongle was dropping the power. Plugging directly gave most power, but the power hub apparently gave a lot more.
They gave me the same solution to get caller ID. Although when someone says I have Caller ID, I would assume the MagicJack would pass on all of the Caller ID data to my device. In this case the device was a phone that was capable of displaying phone numbers and names. Even if they can't pass the name from the phone system, I would've assumed they could have inserted the name from the MagicJack address book when I have given the names I know the callers as. The software dial pad displays it on the monitor screen, so the information is available.