Comment 10 for bug 692677

One of the difficulties here is that
one - there are some inconsistencies when using the same login, it not always the same, though if needed a logout/in or 2 can stabilise and give a clean login

two - there is clearly something different between the Desktop and Classic logins to unity. At this point I'd think any updates/patches/tests need to be run on Desktop > unity to test them, probably more than once (the 2 last updates to compiz highlight that
https://bugs.launchpad.net/ubuntu/+source/compiz/+bug/691561

three - when switching logins there is a good possibility of having the compizconfig settings for that profile unset, which then leads to having to re-enable to match their respective defaults. (if that matters ?

four - making some changes to compizconfig will crash compiz - it may take a restart and or a couple of logout/ins to return a clean load of that respective interface/profile

So - booting to a clean load of Classic > gnome-panel nvidia-settings works fine BUT it's not guaranteed to work 100% of the time, the same can be said for the Classic > unity login. If it fails (rare), it does so in same manner as the Desktop > unity. The difference is a logout/in will always fix in the former 2, nothing fixes Desktop > unity (except below

The one constant here seems to be the failure of the window decorator plugin, so -

Booting to a clean load of Desktop > unity with the window decorator plugin previously disabled, then nvidia-settings works fine