I have a curious problem that's just sprung up, after changing from using plain-old-pointers to using boost::shared_ptrs internally in my data structures (stl hash_map and map) The problem is that while the XML archive works correctly, both text and binary fail (they all used to work). This is using gcc 4.0.1 on darwin and VC8 on windows, boost version is 1.34.1 The failure occurs while unserializing an archive, specifically when trying to read back a shared_ptr to an already unserialized object. In the archive, it shows the object (pointer) as an object_reference (the same reference id in XML and text). While the XML version reads the pointer back correctly, the text version fails and returns NULL. I have not determined the exact reason why the text version fails (it doesn't throw, just returns NULL). The serialization does not appear to have any problems. Since my actual code is reasonably complicated, and I haven't created a simplified version that demonstrates the problem, I'm not including code now - I'd just like to find out if this sounds familiar to anyone, that is, working under XML but failing under text and binary. It does appear to be shared_ptr specific, too, since everything was working before replacing naked pointers with shared_ptrs.