[Boost-users] [serialization] different behaviour between xml_wiarchive and binary_wiarchive

In my application I'm trying to serialize data alternatively to xml_wiarchive or binary_wiarchive. Writing and reading XML works without any problems. Binary writing seems to work too, but reading the file throws an exception with exception_code 'unregistered_class'. What I do is reading the XML data, writing binary and reading binary back in. I thought there should be no difference which kind of archive I use. Am I missing a point? I would be thankful for any hint. I know that it is hard to guess where the problem might be without seeing any code, but I by now I was not able to create some simple example which shows the same behaviour. I'm using Windows XP (SP2) with MSVC 8.0. Thanks. Oliver