try disabling any add-in that acrobat reader prof 8.1.2  has enabled or
remove acrobat reader prof 8.1.2 .

We are having similar problems, but cannot tie it in with anything like
Acrobat as you have.  We don't see any adobe add-ins in our list.  Our
reading pane just goes dead ... displaying whatever was displayed there
last, such the message list if the reading pane was turned off for a minute.

Office Diagnostics 2007 and rebooting does not fix the problem either.  We
are also noticing that many, or sometimes all, of our contact business cards
are displaying as blank cards.

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