--- net-snmp-5.7.1/agent/mibgroup/agentx/client.c	2012-08-27 10:22:10.000000000 -0500
+++ net-snmp-5.7.1-patched/agent/mibgroup/agentx/client.c	2012-08-23 15:44:55.000000000 -0500
@@ -130,8 +130,10 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return 0;
 
-    if (!response)
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "open NULL response\n"));
         return 0;
+    }
 
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
@@ -216,7 +218,13 @@
         return 0;
     }
 
-    if (response->errstat != SNMP_ERR_NOERROR) {
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "registering NULL response\n"));
+        return 0;
+    }
+
+    if ((response->errstat != SNMP_ERR_NOERROR) && 
+	(response->errstat != AGENTX_ERR_DUPLICATE_REGISTRATION)) {
         snmp_log(LOG_ERR,"registering pdu failed: %ld!\n", response->errstat);
         snmp_free_pdu(response);
         return 0;
@@ -267,6 +275,11 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return 0;
 
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "un-registering NULL response\n"));
+        return 0;
+    }
+
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
         return 0;
@@ -331,6 +344,11 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return NULL;
 
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "register index NULL response\n"));
+        return 0;
+    }
+
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
         return NULL;
@@ -396,6 +414,11 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return -1;
 
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "un-register index  NULL response\n"));
+        return 0;
+    }
+
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
         return -1;              /* XXX - say why */
@@ -426,6 +449,11 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return 0;
 
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "add agentcaps NULL response\n"));
+        return 0;
+    }
+
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
         return 0;
@@ -455,6 +483,11 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return 0;
 
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "remove agentcaps NULL response\n"));
+        return 0;
+    }
+
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
         return 0;
@@ -482,6 +515,11 @@
     if (agentx_synch_response(ss, pdu, &response) != STAT_SUCCESS)
         return 0;
 
+    if (!response) {
+        DEBUGMSGTL(("agentx/subagent", "ping NULL response\n"));
+        return 0;
+    }
+
     if (response->errstat != SNMP_ERR_NOERROR) {
         snmp_free_pdu(response);
         return 0;