how to set title in installer interface

[kin boster]

hi all:
       I create a udeb package to add a user interface in debian installer
based lenny.
       When run to my  add interface the title line display two exclamation
mark( ! ), not a title,
       and syslog display:
      " Mar 15 02:59:13 main-menu[1079]: WARNING **: Unable to set title for
my_test-udeb."
      But I have already set title in my code "db_settitle my_test/title",
and here is templates
Template: my_test/title
Type: title
Description:This is my_test

      any advices?
      Best Regards

      Boster