I have save to postscript format from Indesign CS2 before distilling to pdf format. My platform is Max OS X, 384 MB ram.

Issue:
When I distill the ps in Acrobat Distiller 6 the following appears:
1. Missing letters, e.g "try" become "ry", degree sign missing, close brackets missing. Not consistently the same character. Brackets or degree sign will appear in other pages.

2. Letters replaced with other letters, e.g. "collected" become "cowwected", (400C) become (400 Cw etc.

The above problem can be resolved if I use the same ps file to distill in Acrobat 4.0.
Acrobat 4.0 and Acrobat 6.0 has the same setting options when I distill.

Why? What is missing in Acrobat distiller 6?

Was it because I cannot convert to pdf via postscript format? I must use the export to pdf feature in InDesign?

What are the steps be take to avoid the issues above?