CakePHP e Wampserver

Olá amigos, gostaria de saber por que em meu servidor Wampserver aperecem tantos warnings, gostaria de saber como remove-los, será que alguém pode me ajudar?

Esses são os warning que aparecem para mim.

Warning: SplFileInfo::openFile(C:\wamp\www\cake2\app\tmp\cache\persistent\cake_core_file_map) [function.SplFileInfo-openFile]: failed to open stream: No error in C:\wamp\www\cake2\lib\Cake\Cache\Engine\FileEngine.php on line 292

Warning (2): SplFileInfo::openFile(C:\wamp\www\cake2\app\tmp\cache\persistent\cake_core_cake_dev_pt-br) [function.SplFileInfo-openFile]: failed to open stream: No error [CORE\Cake\Cache\Engine\FileEngine.php, line 290]

Warning (512): _cake_core_ cache was unable to write 'cake_dev_pt-br' to File cache [CORE\Cake\Cache\Cache.php, line 310]