Ubuntu And "New" Releases of Linux...
First. I have 10 years of experience in Linux and BSD Unix. I have installed, and configured all of the major Linux distributions for both server and desktop use. Including, but not limited to: RedHat, Ubuntu, SUSE, Slackware, Debian(my favorite), Mandriva, and most associated variants.
Now that is out of the way. Here is some notable advice from experience.
1. A new release of ANY software, no matter how many times it was alpha or beta tested before release, will have unexpected bugs. This includes using new kernel releases!
2. I have always been skeptical of simply "upgrading" a fully configured operating system. The best way is to always back up everything. Don't forget the config files in your "~/home" and "/etc" directories. And then perform a "clean Install". Wipe the drive, and start fresh. This will reeeeally help in reducing the number bugs you may encounter. At least you will know it wasn't a confilct from the previous version. Which can wreak a lot of havoc in some cases.
3. Early adopters of new OS releases will ALWAYS experience bugs.
If you are a newbie, go back to your previous version and wait for some of the major bugs to be resolved first.
If you are technically experienced with Linux(Ubuntu) then stop complaining to the blogs and keep sending Ubuntu those bug reports. It's important so they can be addressed in a timely manner.
Early adopting a new release is NOT for newbies or the faint-of-heart.
Eventually the bugs in "Karmic Koala" will be worked out. Be patient.
And before anyone is "quick to judge" a Linux distribution.. M$ has its own buggy history: Win3.0, Win95a, WinME, Vista. Win7 will and already has coughed up a few of its own major bugs.
Regular users of Ubuntu, be patient.
Experienced, technical Ubuntu users, Send Ubuntu Those Bug Reports.