You can use FERROR() to determine a cause of failer and try to eliminate it.

>Three questions:
>1. I'm wondering how to release (or what to do with) a file handle created with
>FOPEN if, for some reason, FCLOSE fails to close it.
>
>2. If the file handle can be released by other way, that will close the file?
>
>3. If the file can't be "unhandled", apart of the problem that the file can't be
>used by other processes, how much that is harmfull for my application?
>