I recently had the necessity to install Matlab on a Linux machine running Ubuntu 8.04 and I have encountered a few quirks here and there.
First it is a good idea to run
unset LANG before running Matlab, otherwise certain GUI components, such as the directory selection modal dialog, will not run properly.
Second, it is necessary to modify the options related to mex, the C (or Fortran) to Matlab interface. The reason is that with GCC 4.x it is no more necessary to link against libstd and trying to do so will cause quite a bit of hassle (you can solve it on Fedora by installing gcc-compat, which is not available on Ubuntu, as far as I know). The solution is then to modify the file
~/.matlab/R14/mexopts.sh and simply remove the
-lstdc++ option from the gcc section.
Finally I would suggest to run Matlab from console: KDE does not get along well with it.
Hope this helps.