Hello, on the Windows platform, in my own application (built in unicode char econding) I am experiencing this problem with Boost 1.38: if I change the locale before loading an xml archive, then the application will hang in the loading of the archive file. I must add that this only occurs in a Release build on Windows Vista, but it never occurs on Windows XP. Also, if I run the application on Vista with the Compatibility Mode set to Windows XP SP2, it does work and does not hang while loading the archive. I tryed to get a stack trace with a ReleaseWithDebInfo on Windows Vista, here it is: Warning: stack unwind information unavailable. Following frames may be wrong. application!std::vector ::push_back+0xblabl1 application!std::vector ::push_back+0xblabl2 application!std::vector ::push_back+0xblabl3 application!boost::archive::detail::oserializer ::save_object_data+0x18b50 application!0xblabla Any hint what to look at to resolve this issue? Many thanks. Best Regards, Luca