Ok to rule out the different executables being the issue (thought typeid might be the issue), I've made them into one executable. Still no difference though. -----Original Message----- From: boost-users-bounces@lists.boost.org on behalf of Sohail Somani Sent: Mon 3/26/2007 9:13 PM To: boost-users@lists.boost.org Subject: [Boost-users] [serialization] Assertion `new_cid == cid' failed -fails on gcc, works on msvc Hi, I am serializing/deserializing a polymorphic class and I am having the above issue upon deserialization where it fails on gcc and works in msvc. The serializer and deserializer are implemented in two different executables. Should that be an issue? All the object files *except* the serialize/deserialize/main functions are the same in both executables. In the gcc case, its comparing new_cid=2 against cid=1 (if that helps at all!)