Guest Additions modules of VirtualBox don't work for Ubuntu 14

How I solved it (by googling):

1. Follow steps from here -> http://www.sysads.co.uk/2014/04/install-virtualbox-guest-additions-ubuntu-14-04/
2. Update your VirtualBox. The one I tried is version 4.3.14.

Maybe step 1 is not necessary and you can skip to step no 2. You can try and comment here with the result.