Some Ubuntu-related tricks will be descibed here.
X
If X gets totally hosed (i.e. you don't have any graphical interface at all), try running "sudo dpkg-reconfigure xserver-xorg" and select a very basic video configuration, using the "vesa" video driver, and accepting all the default options.
On Dell machines with fancy Nvidia video cards, there is a proprietary video driver available. Running "nvidia-xconfig" will switch over your X configuration to use the Nvdia drivers. See also http://www.cs.cornell.edu/w8/~djm/ubuntu/feisty/#nvidia-driver.
Matlab
Matlab R2007a crashes frequently in Ubuntu Feisty. Apparently most of these problems are actually the fault of Java, on which Matlab relies heavily. By setting a few environment variables and upgrading the java JVM, most of these quirks can be fixed.
Simulink crashes
Install a new JVM by typing:
sudo aptitude install sun-java6-jre sun-java6-fonts
Now set the MATLAB_JAVA environment variable to point to the new JVM. I start Matlab via the following shell script (which I put in ~/bin):
export AWT_TOOLKIT=MToolkit export MATLAB_JAVA=/usr/lib/jvm/java-6-sun-1.6.0.00/jre eval `~/ligotools/bin/use_ligotools` /usr/local/bin/matlab $*