cjk fonts issue in pdf

hgk

I have windows XP and supplemental language support(Install files for East Asian languages).

I am using birt 2.2.1. My system locale is English.

I created a pdf file with some chinese and korean characters. When I opened the pdf file using Adobe Reader 9.0, it prompted me to install Korean fonts and chinese fonts. I did not change anything in platformpluginsorg.eclipse.birt.report.engine.fonts_2.2.1.v20070823 folder.

I thought fonts are embedded into the pdf file. Is this not correct? Why did adobe reader prompted me to install the fonts?

My understanding is that the character glyphs are rendered in the pdf document at the pdf creation time. Could someone point me to a detailed document on how pdf file is generated.

Thanks,
Bindu