Further to this thread, I have a client that wants double-byte characters in titles and other custom fields. I didn’t think it would be a problem, indeed, SAEFs seem to be breaking (white page) and in the CP I’m getting “Unable to create valid URL Title for your entry” when I enter, for example, this: 漢字

We’re running:
Build:  20080710
PHP Version 5.2.5
MySQL: 5.0.37-log

These seem to be the MySQL variables that may be related to the issue:

Client needs this stuff running by Tuesday… does anyone have a magic bullet here?

Alright, so, ExpressionEngine follows the W3C standards for URLs; which includes never using high ascii characters in URLs. 

The difficulty here is that there is no direct translation from those characters to a non-High Ascii equivalent, so ExpressionEngine can not automatically generate a URL Title.

You have a few options here - one is to create your URL Title using normal characters. The other is to create your title the way you did, but then specify the URL title yourself.  Or you could uses standard characters for your title, let it be auto populated, and use a custom field for your specific language title and only output the latter in your templates.