To prevent your bash command history from being overwritten when using multiple shells (and who doesn't have more than one xterm open?), put this in your .bashrc:
# Supposedly prevents the command history from being overwitter by # multiple shells shopt -s histappend
$ sudo apt-get install gsfonts-x11 msttcorefonts
Found here: http://ubuntu.wordpress.com/2005/09/page/2/