Erratic behavior after a few days

[1DoLittle]

After a few days of operation the system becomes erratic and eventually unuseable.
Setup: Host windows 10, guest (2) MX 16 XFCE and Mint 18.1 XFCE currently installed (Previous Mint 18.1 MATE and Mint 17.3 MATE had same problem)
Virtualbox v 5.1.12r112440 (earlier v 5.1.14 became unuseable).
Computer: Tower with Intel i7 CPU 64-bit 930@2.80GHz
Only fix I can find is to uninstall VB and reinstall same version.
Uninstaller used REVO 64 v2.0.0 with advanced scan and deleting all scan items.
After uninstalling VB the computer is shutdown, power cord removed >1minute, then restart windows 10 and reinstall VB
Now everything seems normal.
The attached JPG is showing the earlier stages of the problem.
Note where the cursor moved.

[socratis]

After a few days of operation the system becomes erratic and eventually unuseable.

I'm sorry, I read it three times and I don't understand what the problem is. Could you try again?

If English is not your first language, post it in your native language and we can use Google Translate (https://translate.google.com).

[1DoLittle]

Socratis: I will try to clarify the problem - it is unlike any problem I have ever encountered.
The following screenshots have several notes that should describe what is occurring.
A quick summary is after several days of operation, while left unattended the cursor moves and popups occur. This would not be a problem except the time will continue to shorten to seconds and the system becomes unuseable. The only solution found is to reinstall VB.

[socratis]

A picture can worth 1000 words, but sometime a few words can help a lot more than a picture, so let me see if I understand this correctly:

• While left unattended and without any mouse input (moving, clicking, right-clicking) you see that the mouse has moved and pop-ups show up, just as if a user had right-clicked on the screen. Is that correct?
• "The system becomes unusable".I still can't understand why you can't use it. Is the mouse erratic? Do you lose keyboard input? Is the guest frozen? Is the host frozen?
• Re-installing VirtualBox fixes the issue for a couple of days.
• How are you accessing the VM? VNC? VRDP? Directly?

I'd like to see the VBox.log from a run where you actually notice the erratic behavior, not from any run:

1. Start the VM. Not from a saved or paused state. Clean start.
2. Take the steps required to generate/observe the error. Leave it unattended until you notice the problem.
3. Shut down the VM (if it hasn't aborted by itself). Not saved, not paused. Completely shut down. If you can't shut it down by normal means, close the VM window and select "Power off".
4. Right-click on the VM in the VirtualBox Manager. Select "Show Log..."
5. Save it (just the first log), ZIP it and attach it in your response (see the "Upload attachment" tab below the reply form).