php - PHP unlink woes

Question

I am using php function unlink() as you most probably assumed but it seems to be giving me a false negative... It gives me this warning:

Warning: unlink(/home/blackboa/public_html/classes/lib/test.lang) [function.unlink]: No such file or directory in /home/blackboa/public_html/modules/lang_manage/main.php on line 41

But the file does get deleted.

Here is the php code for the specific function:

function delete_lang_file($file){
   if(preg_match('#\.lang#', $file) && !preg_match('#blank\.lang#', $file)){
        unlink(CLASSES_PATH."lib/".$file);
   }
}

There is no existing file handlers when this function is executed however file_get_contents() and an fopen() fwrtie() and fclose() set are used in other functions which are never called in the same execution of unlink().

Is there anything I am doing wrong, forward slash instead of backslash maybe?

Thanks,

Fraser K