Here is an example:
Please click on the Windows Orb it is located in the lower left of the screen, it was the Windows Start icon in Windows XP.
Please click Devices and Printers
Double click on Adobe PDF
Please Click on Printer and select the Adobe PDF Settings Tab.
Uncheck the option "Rely on System Fonts only; do not use document fonts"
Note: if "Rely on System Fonts only; do not use document fonts" option is already toggled off please toggle it on and click OK
Some have reported opening PDF documents from the web within Firefox 4.0 Beta. And the document displays like the example above. If this occurs update Firefox 4 beta to Firefox 4.0.x the issue was corrected in a minor patch release.
While in Firefox 4, click Help
Scroll to and select Check for Updates...
Follow the prompts to complete the update.