I have a related problem... I added a second zen cart to our database after upgrading to 1.39. All good, except I had trouble getting the Collation set to utf8_general_ci for the new tables.
So I ran a sript that updated all of the tables to utf8_general_ci.

That worked, but now my 1st shopping cart, which always displayed Japanese properly, is displaying garbage characters.
However, when I go in to Admin and look at the source (e.g. Product Description) the Japanese is fine. So it's all still correctly in the datablase.

The encoding of the cart comes up as utf-8,
<html xmlns="http://www.w3.org/1999/xhtml" dir="ltr" lang="ja">
and
<meta http-equiv="Content-Type" content="text/html; charset=utf-8" />)

and no changes I can make via the browser make the Japanese not look like garbage.

But still, when I log in to the admin and try to edit the text, it's fine (real Japanese characters).

Finally, in the cart view, SOME Japanese is displaying correctly. It is the Japanese from the php files. So any boilerplate text from the files displays properly in the cart, and any database text displays properly in Admin, but it is trashed in the cart.

Sorry for describing that several different ways. It's not a problem I've seen before.

Thanks!