Adobe CS4 and CS5 officially doesn't support Arabic. Instead, there is a separate ME version (Middle Eastern) which supports left-to-right languages.
Typotheque designs and develops Unicode-compliant fonts. Below are some instructions for using Unicode fonts to set Devanagari texts.
In order to use Arabic fonts, you need to use special versions of InDesign, PhotoShop or Illustrator. These versions are labeled ME (Middle Eastern) and support bi-directional text setting for Arabic, Farsi and Hebrew. The regular version of Adobe CS3 doesnʼt support Arabic text setting.