One thing I've had trouble with in the past with Symbol font is having multiple versions of it on the machine. Check your fonts folder. If you have both a PostScript (Type 1) Symbol font and a TrueType Symbol font, try removing the PostScript version.
Also, make sure the arbortex.ttf font is properly configured on the machine. You may have to right click the font file and select "Install" to have it recognized by Windows.
If that doesn't help, maybe you can provide more information about the font you are trying to use (if it's not the standard Windows Symbol font), what kind of stylesheet you are using, etc.