Hi Damian,
I suffered a similar problem which I reported to the forum:
http://hdf-forum.184993.n3.nabble.com/Deploying-HDF5DotNet-causes-Could-not-load-file-td402678 3.html
My issue was missing C++ runtime DLLs:
Msvcp100.dll
Msvcr100.dll
I got these from the 'Binaries' mentioned at http://hdf5.net/
I included these two DLLs in the runtime path of my app. so that the HDF5DotNet wrapper can find
them. I guess you would want them in the target path for your deployments as well.
Graeme