Eureka!
Here's what I did to fix my problem:
1. Open Word and go to Tools>AutoCorrect Options
2. Go to "AutoFormat" tab and CLEAR "Straight quotes" with "smart quotes"
3. Go to "AutoFormat As You Type" tab and CLEAR "Straight quotes" with
"smart quotes"
To other interested readers…
I'm not at all technical (or bright!) enough to understand why this worked,
but here's what I know…
My problem with the squares was limited to WEB SITE replies from
SBCGlobalYahoo and Yahoo users, which appear to be in US-ASCII. Anyway, it
would seem that the web email program for Yahoo was not correctly
interpreting whatever "smart quotes" are. Then when that interpretation was
returned to Outlook as part of the reply, the Word reader was replacing the
quotes with "little squares".
When I CLEARED the options listed above, the responses to any new emails
sent to these sites no longer contained squares.
I'll also add that I do NOT have Spamfighter for Outlook. I bring this up
only because the removal of the free version of Spamfighter has been
mentioned in other threads as a solution to this problem.
Maverick, please let us know if this solution works or not for you.