I recently started using webstorm in ubuntu 14, and all of my "special" keys - tab, special characters, etc - work except for all 4 of the arrow keys. When I press them nothing happens. I went into project/keymap (thinking that might be where the fix is), and changed it from default xwin to visual studio and eclipse but that didnt make a difference (I restarted ws each time). I saw you have a "move tab left and right" plugin, but the tab key isnt the problem, so I didnt install it.
This has been consistent, they have never worked. They do work if I open the file in the default ubuntu simple text editor or vs code. It isnt project specific, I have a few projects and the same thing happens.