===+++ _____________________ !  ALL USERS  !  _____________________ +++===
===+++ READ THIS BEFORE MAKING A COMMENT OR MODIFICATION +++===
  
IMPORTANT 1: Please see the WORKAROUND a few lines below.
  
IMPORTANT 2: Please don't post any "me too message"; use the "Does this
bug affect you?" feature you can find a bit above this bug description
on launchpad.
  
IMPORTANT 3: Do not post anything if you haven't read all comments to
verify that your point hasn't been made. If you feel tempted to stop
reading because there are too many messages, that is a strong indicator
that you shouldn't add even more comments. Developers have a tough time
to find anything if you post redundant stuff. So please abstain from
doing that.
  
=================================================

So here the bug and workarounds.

For example on youtube, whilst it recognises my mouse moving over
various buttons, actual mouse clicks are not recognised. I can navigate
using 'tab' but this is very painful. I can also right click. The
problem doesn't occur with other flash players, e.g. swfdec-mozilla.

WORKAROUND 1: Disable compiz
WORKAROUND 2: Remove flashplugin-nonfree / flashplugin-installer and install from adobe
WORKAROUND 3: Open a terminal and enter:

gksudo gedit /usr/lib/nspluginwrapper/i386/linux/npviewer

Then add: export GDK_NATIVE_WINDOWS=1 before the last line of text

Note: Chrome & Chromium are now working fine without workaround

These workaround's have been verified to work for some users. We don't
need verification of whether or not they work for you.

=================================================