I've tried this issue on VC6 + db4.7.25.0 + win2k, and I could reproduce
error.

I added following patch for investigation.

Index: Lib/bsddb/test/test_replication.py
===================================================================
--- Lib/bsddb/test/test_replication.py  (revision 66483)
+++ Lib/bsddb/test/test_replication.py  (working copy)
@@ -40,6 +40,7 @@
                 self.confirmed_master=True

         def client_startupdone(a,b,c) :
+            print "DBReplicationManager:", (a, b, c)
             if b==db.DB_EVENT_REP_STARTUPDONE :
                 self.client_startupdone=True

@@ -201,6 +202,7 @@
                 self.confirmed_master = True

         def client_startupdone(a,b,c) :
+            print "DBBaseReplication:", (a, b, c)
             if b == db.DB_EVENT_REP_STARTUPDONE :
                 self.client_startupdone = True

And this is result.

DBReplicationManager: (<DBEnv object at 0x00A80148>, 2, None)
DBReplicationManager: (<DBEnv object at 0x00A80148>, 5, 0)
DBBaseReplication: (<DBEnv object at 0x00B35CD0>, 2, None)
DBBaseReplication: (<DBEnv object at 0x00B35CD0>, 5, 13)
DBBaseReplication: (<DBEnv object at 0x00B35CD0>, 7, None)
DBBaseReplication: (<DBEnv object at 0x00B49658>, 2, None)
DBBaseReplication: (<DBEnv object at 0x00B49658>, 5, 13)
DBBaseReplication: (<DBEnv object at 0x00B49730>, 2, None)
DBBaseReplication: (<DBEnv object at 0x00B49730>, 5, 13)