In 16.04, the pointer often times become off-location during editing mode

[cnbiz850]

I run it on VirtualBox hosted by MacBook Pro. Often times when I edit files in an editor, or even rename a file, the pointer's location is shifted by some characters down- and right-ward. It seems to happen after I use the system for a while, and after it happens, it stays until system shutdown.

I also tried Xubuntu 16.04 and it has the same problem.

Anyone know how to fix the problem?

[cnbiz850]

When it happens, it appears toggling VirtualBox's Mouse Integration on the menu resets the pointer. So probably this is a problem of VirtualBox, but this does not affect guest Xubuntu 15.10, it only happens with 16.04.