Did you add a blink command or something similar? On my terminal, the whole screen is constantly showing then hiding then showing again in 1 second intervals. Mac OS X 10.6.8, Terminal 2.1.2.
Very odd - na, that's a bug and not a feature, I'm just throwing color coded Braille characters at you ;) Most likely related to your Terminal version, http://iterm2.com might help.
