Comment 22 for bug 227344

This means that now Lucid uses $zone$ syntax, while karmic was fine with %zone% (at least, with dlz-mysql)

Also, http://bind-dlz.sourceforge.net/mysql_driver.html still reports %% as the correct way to write the config file.

I cannot find any reference anywhere of this syntax change, it took me a few hours to understand what was wrong.
Proper documentation should be included in the ubuntu package.

Thank you,
Roberto Sebastiano