I took me a while to figure this is out, but I finally did. When ccleaner is minimized to the system tray, it constantly (every 30s or so) steals the focus, so that -for example- I can not scroll a web page or type anything, because the input is not directed to the browser anymore.
For example, watching a video on youtube in full screen, after a while, i can not return to normal mode by pressinng ESC, it doesn't work, i have to click on the image to get the focus back to the browser and then i can press ESC.
Same thing happens when watcching a video, after a few seconds the mouse wheel stops responding and I have to click somewhere in the page to get the focus back.
I tried a million things until I closed the systray icon: immediately fixed the issue.
this is EXTREMELY ANNOYING and it disrupts whatever I'm doing every 30s or so.
and it's not only the browser. For example, I open the task manager and after a few seconds, i can not scroll through the list of running processes with the mouse wheel, because ccleaner stole the focus.
and so on...
Edit: It also happens while minimized to the taskbar, you can phisycally see the focus go to ccleaner (the ccleaner taskbar icon gets hilighted by itself)
Please fix it!