Chinese characters scramble after a while

The problem I am currently facing is that the Chinese characters that
are posted on my site which are encoded with UTF-8 become scrambled for
some reason overnight (I check the next morning). All my pages on the
application are headed with
I attempted to use the solution provided on this page
but it did not fix the problem.

Also, these Chinese characters are details, which I store in a DB2
database which has code set to UTF-8, and are grabbed from the database
when a user visits the page displaying the information. So based on this
I suspect that the problem lies with how the data is grabbed from the
database to the server(just a guess). The versions I am using are:
ruby 1.8.7
rails 1.2.6
mongrel 1.1.3

In my database.yml file the encoding is set to utf8