FTDTTYUSB lost after umpteen installations

I have Arduino 17 in applications folder. When i open it i can select the board i am using Lilypad. But when i go to serial only the blue tooth and modem selections show up . I am using the usb ports with a breakoutboard. I am looking for the ttyusb. Have tried reinstalling the FTDI for intel multiple times NOTHING.Where are they hidden? why won't they install on my computer? Should i deinstall every arduino thing ans start over. FRUSTRATED When i connect to the Lilypad i get a message usb port is being used. Working on a macbook with 10.6. HELP