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If you are using Redhat 9 you will need to edit the /usr/local/Acrobat5/bin/acroread (or similar script) and add the following lines near the top
LANG=C export LANG
This is to fix a problem with character sets that will manifest itself as
Warning: charset "UTF-8" not supported, using "ISO8859-1". aborting
6 pages link to AcrobatReader: