diff -r '--exclude=*~' -u openmpi-1.6.3/ompi/mca/coll/tuned/coll_tuned_alltoallv.c openmpi-1.6.3.patched/ompi/mca/coll/tuned/coll_tuned_alltoallv.c
--- openmpi-1.6.3/ompi/mca/coll/tuned/coll_tuned_alltoallv.c	2012-04-03 15:30:17.000000000 +0100
+++ openmpi-1.6.3.patched/ompi/mca/coll/tuned/coll_tuned_alltoallv.c	2013-01-24 15:13:25.838528015 +0000
@@ -118,6 +118,7 @@
     int i, size, rank, err;
     char *psnd, *prcv;
     int nreqs;
+    int sendto, recvfrom;
     ptrdiff_t sext, rext;
     MPI_Request *preq;
     mca_coll_tuned_module_t *tuned_module = (mca_coll_tuned_module_t*) module;
@@ -154,13 +155,14 @@
 
     /* Post all receives first */
     for (i = 0; i < size; ++i) {
-        if (i == rank || 0 == rcounts[i]) {
+        recvfrom = (rank + size - i) % size;
+        if (recvfrom == rank || 0 == rcounts[recvfrom]) {
             continue;
         }
 
-        prcv = ((char *) rbuf) + (rdisps[i] * rext);
-        err = MCA_PML_CALL(irecv_init(prcv, rcounts[i], rdtype,
-                                      i, MCA_COLL_BASE_TAG_ALLTOALLV, comm,
+        prcv = ((char *) rbuf) + (rdisps[recvfrom] * rext);
+        err = MCA_PML_CALL(irecv_init(prcv, rcounts[recvfrom], rdtype,
+                                      recvfrom, MCA_COLL_BASE_TAG_ALLTOALLV, comm,
                                       preq++));
         ++nreqs;
         if (MPI_SUCCESS != err) {
@@ -171,13 +173,14 @@
 
     /* Now post all sends */
     for (i = 0; i < size; ++i) {
-        if (i == rank || 0 == scounts[i]) {
+        sendto = (rank + i) % size;
+        if (sendto == rank || 0 == scounts[sendto]) {
             continue;
         }
 
-        psnd = ((char *) sbuf) + (sdisps[i] * sext);
-        err = MCA_PML_CALL(isend_init(psnd, scounts[i], sdtype,
-                                      i, MCA_COLL_BASE_TAG_ALLTOALLV,
+        psnd = ((char *) sbuf) + (sdisps[sendto] * sext);
+        err = MCA_PML_CALL(isend_init(psnd, scounts[sendto], sdtype,
+                                      sendto, MCA_COLL_BASE_TAG_ALLTOALLV,
                                       MCA_PML_BASE_SEND_STANDARD, comm,
                                       preq++));
         ++nreqs;