google app engine 无法更新 rollback

不知道什么原因，进入更新一个页面的时候，gae提示下面信息：

Initiating update.
2008-12-29 21:05:56,296 ERROR appcfg.py:1336 An unexpected error occurred. Aborting.

Error 409: --- begin server output ---
Another transaction by user * is already in progress for this app and major version. That user can undo the transaction with appcfg.py's "rollback" command.--- end server output ---

*处是你的用户名看字眼是要用rollback 命令修复吧，于是命令提示符里面输入：

appcfg.py rollback youapp/将youapp 替换成你的app的id 即可

然后该怎么更新就怎么更新