Can't hide these phantom lines in a part file?

I have a simple part (modeled by somebody else or imported).

It has some phantom lines that I can't hide.

In 3D model space, If I set to "wireframe, no hidden" there are still hidden lines that shine through.

Same thing happens if I make a drawing from this part.

It may be a configuration setting rather than part issue, since the lines do not show up on other people's machines. Creo 11.

Any help will be appreciated.