Zend Cache - problem with deleting cache files

Question

I have an strange problem with Zend Cacke (File Backend) running on linux with apache and php 5.2

The files are stored in /myspace/tmp1

Directory has the persmission:

drwxrwxrwx  2 nobody nogroup 8192 2010-09-20 13:35 tmp1

The created temp file has the following permissions:

-rw------- 1 nobody nogroup  317 2010-09-20 13:40 content---a51607ba255692370eae1155c7f45856

If if i do:

$cache->clean(); inside my script, than the method returns true, but the file is not removed (no error in php error log).

On my local development machine running under win xp everything works fine. I think it is some kind of permission problem? The Apache is running as "nobody"

Any suggestions are welcome!