This means that some application on the *nix server has terminated abnormally and a memory dump of the crashed application is present in those .core#*$!X files.
thanks.. i just received a reply from my host.... they say....
we have debugged the problem.it seems that it was in the configuration of the zend optimizer and the ioncube loader.we compiled the webserver again and all problems should be solved..
Could well be. If an application due to a bug writes outside its allocated memory (e.g. NULL) this implies the application will be stopped by the OS and the OS will create such a core file. With an appropriate debugger this file can be examined in search for the potential problem.