It feels like it is a keyboard problem because the symptoms always show after pressing a key.

In most instances, a line I am typing in "gedit" at the correct place in the text is unexpectedly continued a few lines downward even though no arrow key has been pressed. In another instance, I click "new thread" in Linuxquestions, a new window opens asking for a title, after entering the title I click "Click Here to Find Similar Threads", a new smaller window opens on top of the existing one and shows the existing options but as soon as I select (click on) one of these options, the main Linuxquestions window disappears and there is no option of "going back" to it and no "back" button to click.

Any advice?

If the keyboard needs cleaning, how do I do that? I found a few cleaning hints about separate keyboards but nothing about laptops.

Thank you for your help.

I can see your debian logo, which makes me believe you're using epiphany browser, Try using the iceweasel browser. Someone else will help you with gedit problem . Let me know if iceweasel works for you.

When new thread is clicked it opens new window (similar threads) after selected thread new window opens, there is no back only option to close. Similar threads windows stays in background (hidden).

1 members found this post helpful.

This is using Iceweasel and the missing window is not just hidden or minimized, it is gone without a trace (on the screen).

Have you checked browser settings under Edit>Preferences
3 things come to mind

Tabs
1. Open windows in new tab instead.
2. Always show tab bar.

Privacy
3. Remember History