Timbo,
Please include NX version you're using when you post. What kind of lines do you wish to break? Geometry from the model, dimension extension lines? Can you post a picture of what you want to do?
Tim Flater
NX Designer
NX 9.0.3.4 Win7 Pro x64 SP1
Intel Xeon 2.53 GHz 6GB RAM
NVIDIA Quadro 4000 2GB