Are the LEDs toggling as expected when passing over the line? I found it useful to leave the robot disabled, and simply push it to pivot over the lines. Turn the trim knobs on the sensors if necessary using the LEDs to identify the value of the sensor.
The tutorial at
http://decibel.ni.com/content/commun...#/?tagSet=1001 in the lower left will lead you through some things to think about.
The stop after four seconds is happening because the code interprets three sensors true differently before four seconds and after. After four seconds, it assumes the robot has reached the T and it halts. Before four seconds, it assumes it is the Y or a sharp angle and keeps going.
Also, if your robot has only driven two feet in four seconds, it sounds like the gearing is far different from the kitbot. You may need to adjust the forward speed, the Y value to make better progress.
Greg McKaskle