Uninstall gnome-screensaver, install ubuntu packages:
You’ll also need to setup the screensaver to auto-start when you log-in. Search for “Startup” in Unity, then add an item in that utility, pointing to /usr/bin/xscreensaver
Additionally, you’ll (probably) want to remove the unity-lens-shopping package too – it slows the unity search panel down massively, and – for me at least – will never do anything useful. If I want to search amazon, I’d be on the amazon website.
Other packages you’ll be wanting at some point:
mono-complete (required by keepass2; don’t just install the ‘mono’ package)
There’s massive kinks involved with keepass2 on linux (because of mono) – and the fact that Ubuntu has a script to start keepass2 (/usr/bin/keepass2 is a shell script, and so is not what you configure the keefox plugin for the location of KeeFox (that’d be /usr/lib/keepass2 instead).
Add another auto-startup for keefox by adding /usr/bin/keefox2 in the startup programs (like you did for xscreensaver, above).
I’m sure there’s more, but that’ll do for now. When something occurs to me, I’ll put it up here.
So far, though, Ubuntu 12.04 has just workedTM for me on this HP laptop.