PHP artisan migrate:rollback 回滚失败

migrate 建了一张 pics 表是成功的

vagrant@homestead:~/Code/v0.plantbabe.com$ php artisan generate:migration create_pics_table
 Created:
 /home/vagrant/Code/v0.plantbabe.com/app/database/migrations/2014_11_03_184739_create_pics_table.php
Generating optimized class loader
vagrant@homestead:~/Code/v0.plantbabe.com$ php artisan migrate
Migrated: 2014_11_03_184739_create_pics_table

但是 php artisan migrate:rollback 回滚失败：

vagrant@homestead:~/Code/v0.plantbabe.com$ php artisan migrate:rollback
PHP Fatal error:  Class 'CreatePicsTable' not found in /home/vagrant/Code/v0.plantbabe.com/vendor/laravel/framework/src/Illuminate/Database/Migrations/Migrator.php on line 301
{"error":{"type":"Symfony\\Component\\Debug\\Exception\\FatalErrorException","message":"Class 'CreatePicsTable' not found","file":"\/home\/vagrant\/Code\/v0.plantbabe.com\/vendor\/laravel\/framework\/src\/Illuminate\/Database\/Migrations\/Migrator.php","line":301}}vagrant@homestead:~/Code/v0.plantbabe.com$

都是全自动产生的，而且类名检查过没有错误。
发现除了users表可以正常migrate和rollback以外，其他表在回滚时都会报一样的错误。最后，我直接把2014_10_23_161115_create_users_table,改成2014_10_23_161119_create_ups_table重做了一遍还是报错。太奇葩了，这问题怎么解决？