csv/Rails 3/ruby 1.9.2p0/mysql encoding problem

I'm having an encoding problem, even though I'm attempting to have all
my data always be in utf-8. Here's the path the data takes:

I have a CSV file that I believe is in utf-8, because I'm looking at
it in a hex editor. One of the words is:

64 65 62 74 6F 72 E2 80 99 73

which translates to:

debtor’s [that is, it contains a smart apostrophe]

Now, I'm reading that string in using:

require 'csv'
CSV.foreach(fname, :encoding => 'u') do |row|

Then I'm just storing that string using the standard ActiveRecord
method.

In mysql, when I do "show table status;", I get "utf8_unicode_ci" as
the encoding for all the tables.

When I try to display that data in a browser, however, I get a 500
error with the message:

"incompatible character encodings: ASCII-8BIT and UTF-8"

In the header of my page, I see:

Content-Type text/html; charset=UTF-8

I don't know where else to look.

How can I tell what exactly is stored in the database? If I go into
mysql and query, I get a single question mark in place of the
character, but I don't know if that is caused by a translation after
the fact. In other words, I've ssh'd to the centos machine, started
mysql and did a select. I get:

debtor?s

(Note: the page works correctly on my OS X development machine, using
Ruby 1.8.7, so that is making debugging more challenging.)

I have a little more info: I did a mysqldump and looked at that in my
text editor and I see that the word appears to be encoded correctly in
mysql, at least after being run through mysqldump.

It still looks like: 64 65 62 74 6F 72 E2 80 99 73, i.e. "debtor’s"