Just upgrade to latest Ubuntu release Oneiric Ocelot 11.10. My first impression was WOW! no more bugs. Actually I am a bit disappointed with Natty Narwhal Ubuntu 11.04. Lot of bugs and crash with unity and even gnome. Canonical team has worked hard to improve Ubuntu 11.10. Kudos to them.
Unity works smoothly and Gnome will not let you down. If you would like to try them just visit Ubuntu.com to download.