mysqlhotcopy copied nothing without error reporting?

I wrote a shell script using mysqlhotcopy to backup my databases, I
found all databases can be backuped correctly except a database named
'cd', mysqlhotbackup claims to have copied all tables, but the backup
directory
remains empty.

I copied cd to cd_bk, and do mysqlhotcopy, then it works!

I found a bug report at
http://bugs.mysql.com/bug.php?id=812
like this, but this post is in the year of 2003, and the author claims
that the bug has been fixed, and my MySQL is 4.1.22, so I don't think
they are the same problem.

So what's wrong?

Thank you very much.