TI Launchpad MSP430 on Serial in Linux
This isn't too uncommon, especially if your system is a 64 bit system. Make sure you have these installed on your system:


binutils-msp430
gcc-msp430
gdb-msp430
msp430-libc
msp430mcu
mspdebug
srecord
libsrecord-dev
libgmp-dev


After connecting the launchpad, it may take a bit of time (~1min or less) for the system to pick it up. What happens if you have a terminal open that is just monitoring the port like cat /dev/ttyACM0, and you connect/disconnect the unit a few times?

Are you sure you have everything else installed properly? You may need a few extra things if your system is 64 bit, and the newer kernel versions >2.4 may have a bit of a problem with some programs, but nothing that isn't easily fixed. Assuming you use some Debian distro,

sudo apt-get install subversion gcc-4.4 texinfo patch libncurses5-dev zlibc zlib1g-dev libx11-dev libusb-dev libreadline6-dev


There is a How-to: Launchpad programming with Linux article that may help.