Question: Recently all of my applications keep losing focus every minute (or so) for a few seconds (then the window gets the focus back). It is very annoying, since I'm typing most of the time and get interrupted by this behavior. Things worked fine until a week ago and I have no idea what is causing this error, but I noticed the mouse moves to a certain point on one of my screens when this happens.

I would appreciate any advice: it starts to drive me crazy...

Answer: 
I have been experiencing the same problem for quite some months.
Its been quite sporadic and random.
One article that I read (sorry don't have the link) suggested that Dell laptops have this issue.
The problem is due to some bug in the Bluetooth adapter drivers.
So if you are using the internet by Wi-Fi, **turn off the Bluetooth adapter** and see if this solves the problem.
There can be many other reasons for this problem, just wanted to highlight this one among the others.
This sounds like there may be something nasty on your machine.

Check your machine for malware with something like [MalwareBytes](http://www.malwarebytes.org/) to see if you have picked up a little bug.