Using RoboHelp 11 (11.02.240), I created a WebHelp project which contains a Print button on the toolbar.
When running the help in Google Chrome (Version 36.0.1985.143 m), the Print dialog box does not appear.
In Firefox and IE everything works fine.
Running locally or on a web server? It won't work locally as the print button tries to print only the topic and Chrome blocks that since it's considered unsafe when viewed locally.