Thank you for your suggestion, but it seems not working correcttly for the bug of this plugin.
the results as below:
[buildnumber:create {execution: generate-buildnumber}]
Storing buildNumber: 16 at timestamp: 1205242293453
[buildnumber:create {execution: generate-timestamp}]
Storing buildNumber: Tue Mar 11 14:31 CET 2008 at timestamp: 1205242293453
