PDF export (font) from Web Viewer

I have a report that is supposed to be exported to PDF. When the report is deployed to the site it only uses the default fonts (Times New Roman or Helvetica). To improve the presentation I've been testing with Arial Black using the Web Viewer inside Eclipse and it works just fine: the exported PDF file has Arial Black as expected. Once deployed, Arial Black is replaced with Times New Roman in the exported PDF file.

Is there a difference between these viewers? They're on the same computer.

I've also changed the fontsConfig.xml file with the information below:
<font-paths>
<path path="/Library/Fonts/Arial Black.ttf" />
<path path="/Library/Fonts/" />
</font-paths>

I'd appreciate your help. My set up is the following:

Server: OS X Lion
BIRT: 3.7.1
Eclipse: Version: Indigo Service Release 1

Thanks!