Hi robert, We have been in touch about workaround or a better code organisation for avoiding any assert in extended_type_info.cpp @ line#71 if one tries to upload two different classes, each one implemented in its own DLL, see thread http://lists.boost.org/boost-users/2006/02/16839.php. During our discussion, you have mentioned a related "test", but I didn't find it within the boost distribution. So my questions are: 1. Could you give me the name of the test, the names of the test files; 2. Do you have tested my example, see the zip file, that demonstrates the assert; 3. Is it possible to comment the assert code in extended_type_info.cpp? 4. Do you have any other related links? Furthermore any complete recommendation would be welcomed because we are not able to progress in our developments without this issue. Thank you by advance to handle my request. PS: I didn't see your reply to my last message in the boost-user list. Did you miss it? Marc Viala