Matlab 2009a, released on Feb 12, 2009, is installed on all HPC servers. You do not need to make any changes to use the new version of Matlab. If you like to continue using the old version, you can still use it as it is not removed from the servers.
To run Matlab 2008b, just type
/usr/local/matlab/R008b/bin/matlab or matlab2008b.
Please do not hesitate to contact us if you are having any issues.