I have been playing with Ubuntu since 8.04 and have several servers running 64bit 12.04LTS full time. I have used desktop on and off over this time period but have never committed any machine to running desktop full time. I have a HP dv9000 with AMD Athlon x2 and NVidia which I have used with Vista, Ubuntu Studio, 7, and now trying to get 13.10 to run on it without success. After trying both the 64bit and 32bit versions I decided to try 32bit Ubuntu Gnome. It is running ok, but is still somewhat glitchy.
After my first attempt, I did some digging and found out that there are some driver-related issues and would need to install the NVidia drivers. During the next attempt to run Ubuntu Unity I would alt+shift+f1 to get to a terminal and install the drivers. Reboot, and try to go in to Unity. It would "work" for a short amount of time, usually less than 5 minutes, then everything would freeze on the desktop but the mouse. I couldn't get anything to happen or access a terminal. The only way to get out of the situation was to force-restart the system.
I have been playing with Gnome version for the last 2 days and, while it sometimes freezes, it seems to run far more reliably. I can open multiple programs and switch between them, use email, the Internet, all things I was unable to do under Unity.
So, I decided to install Unity on the working Gnome install and, no surprise, it started having the exact same problems when I logged in to it. However, the Gnome environment was the same as before.
This machine was running Win 7 fine before I decided to make it my first full-time Ubuntu Desktop machine, so I am leaning towards a hardware compatibility issue between Ubuntu 13.10 and the dv9000.