Hi I have the same problem on my laptop & desktop. I use a different antivirus software on each computer.
The odd thing was, on my desktop, it was working fine and then one day I logged in and I couldn't use the Enter, shift, ctrl & alt keys. When I changed it to unicode input, all keys worked except the enter key. So when I am trying to do an email, I cannot press the return key for a new line, so it all comes out as one long sentence.