H5Close and H5fflush calls

Hi all,

I am a newbie to HDF5 format and its usages. I am getting the following
error during my runs with the HDF5 close call.

in Close(): close file

        Class: HDF5

        Major: Object atom

        Minor: Unable to decrement reference count

        Class: HDF5

        Major: File accessibilty

        Minor: Unable to close file

        Class: HDF5

        Major: File accessibilty

        Minor: Unable to close file

        Class: HDF5

        Major: File accessibilty

        Minor: Unable to release object

        Class: HDF5

        Major: Object cache

        Minor: Unable to free object

        Class: HDF5

        Major: Object cache

        Minor: Unable to flush data from cache

        Class: HDF5

        Major: ObjeA]

During my reading on HDF5 close and flush calls, understood that, H5FClose
shall flush the data and make the file inaccessible. Where as H5fflush
shall flush the file data to storage from cache based on global or local
scope.

Here are few queries:

1. What happens if i call close on an already closed file ?
2. Can flush call be used after closing all the individual objects, but the
file is not closed as such ?
3. Can flush call be used after closing the file.
4. I read that, it is good to call flush after closing all the open objects
and the file. Is it correct ?

Can some one please point me to good documentation (not the links about
interfaces etc). I am looking for commonly faced problems, errors, in hdf5.

Thanks
Sravan