PS: I use Po4a 0.36-dev(2009-03-01).
2009/3/2 Dongsheng Song <dongsheng.song(a)gmail.com>:
 When I use Po4a in docbook, I got warning:
 Use of uninitialized value in pattern match (m//) at
 tools/po4a/lib//Locale/Po4a/Xml.pm line 1688.
 For example, checkout
 'http://i18n-zh.googlecode.com/svn/trunk/doc/svnbook-ng/', run 'make
 updatepo':
 ---
 Dongsheng Song