Hello, This mail is about Boost.Serialization and more specifically the new release of this library, tagged as 1.36, which can be found via the link: www.rrsd.com http://www.rrsd.com/ ; I've found this link into a specific thread about Serialization and multi-threading. Last week, I've downloaded this new release and tested it in my environment - Windows XP and Visual C++ 7.1.6030; the compilation was done against Boost.1.34.1 trunk and was running with success but I've noticed that some, "not all", old binary archives generated w/ Boost.Serialization 1.34.1 can't be restored with this new version of Boost.Serialization. When I compare the binary files with a file binary comparison software utility it seems that the binary formats between these two versions are not comparables. I would like to know if this behaviour is "normal": i.e. the binary formats between 1.34.1 and 1.36 are not strictly equivalent and that an old binary archive can be declare "not compatible" w/ the 1.36 release. Is this right? Furthermore, is it possible to have the same behaviour w/ an XML or Text Archive format? Could we guarantee a sort of compatibility in the future? And more generally speaking, what is the policy for insuring compatibility between new releases of Boost.Serialization? Best regards, Marc VIALA