HDFView 2.7 opens but doesnt show groups unless I drag the file onto an already open HDFView window


I am using HDFView 2.7 on Windows 7. I generate and HDF5 file using
the C++ bindings. After my hdf5 file is created, I double click it to
open it. HDFView opens but nothing is display in the 3 panes (2
vertical, 1 horizontal). But, if I drag my hdf5 file over either of
the 2 vertical panes, HDFView happily opens my file and the left
vertical pane displays my groups.

Why doesnt HDFView display my groups upon double-clicking my hdf5 file?

Thanks in advance,