Dotted bar not showing?

[Alberto Simões]

Hello

I am running lilypond version 2.17.17 (MacOSX), and something that never 
had happened to me before just occurred:

A dotted bar is not showing.

I am using the standard \bar ":" but the bar do not get printed.
If I use a standard bar | I get it.

Any idea what might be going on?
I do not think I am using anything special on this music, but I can post 
it somewhere if that helps.

Thank you
Alberto