diff --git a/frame/collect_on_comm.c b/frame/collect_on_comm.c
index c573f20e3a..c16517d5bc 100644
--- a/frame/collect_on_comm.c
+++ b/frame/collect_on_comm.c
@@ -69,7 +69,6 @@ col_on_comm ( int * Fcomm, int * typesize ,
   int root_task ;
   MPI_Comm *comm, dummy_comm ;
   int ierr ;
-  int dtype = -1;
 
   comm = &dummy_comm ;
   *comm = MPI_Comm_f2c( *Fcomm ) ;
@@ -91,18 +90,6 @@ col_on_comm ( int * Fcomm, int * typesize ,
     for ( p = 1 , displace[0] = 0 , noutbuf_loc = recvcounts[0] ; p < ntasks ; p++ ) {
       displace[p] = displace[p-1]+recvcounts[p-1] ;
       noutbuf_loc = noutbuf_loc + recvcounts[p] ;
-
-      /* check for overflow: displace is the partial sum of sendcounts, which can overflow for large problems. */
-      /* it is sufficient to check displace[p] since it is greater than sendcounts[p] */
-      if ( (displace[p] < 0) || (noutbuf_loc < 0) )
-        {
-#ifndef MS_SUA
-          fprintf(stderr,"%s %d buffer offset overflow!!\n",__FILE__,__LINE__) ;
-          fprintf(stderr," ---> p = %d,\n ---> displace[%d] = %d,\n ---> noutbuf_loc = %d,\n ---> typesize = %d\n",
-                  p, p, displace[p], noutbuf_loc, *typesize);
-#endif
-          MPI_Abort(MPI_COMM_WORLD,1) ;
-        }
     }
 
     if ( noutbuf_loc > * noutbuf )
@@ -114,23 +101,27 @@ col_on_comm ( int * Fcomm, int * typesize ,
 #endif
       MPI_Abort(MPI_COMM_WORLD,1) ;
     }
-  }
 
-  /* handle different sized data types appropriately. */
-  ierr = MPI_Type_match_size (MPI_TYPECLASS_REAL, *typesize, &dtype);
-  if (MPI_SUCCESS != ierr) {
-    ierr = MPI_Type_match_size (MPI_TYPECLASS_INTEGER, *typesize, &dtype);
-  }
-  if (MPI_SUCCESS != ierr) {
+    /* multiply everything by the size of the type */
+    for ( p = 0 ; p < ntasks ; p++ ) {
+      displace[p] *= *typesize ;
+      recvcounts[p] *= *typesize ;
+
+      /* check for overflow: displace is the partial sum of recvcounts, which can overflow for large problems. */
+      if (displace[p] < 0) {
 #ifndef MS_SUA
-    fprintf(stderr,"%s %d FATAL ERROR: unhandled typesize = %d!!\n", __FILE__,__LINE__,*typesize) ;
+        fprintf(stderr,"%s %d buffer offset overflow!!\n",__FILE__,__LINE__) ;
+        fprintf(stderr," ---> p = %d,\n ---> displace[%d] = %d,\n ---> typesize = %d\n",
+                p, p, displace[p], *typesize);
 #endif
-    MPI_Abort(MPI_COMM_WORLD,1) ;
+        MPI_Abort(MPI_COMM_WORLD,1) ;
+      }
+    }
   }
 
-  ierr = MPI_Gatherv( inbuf,     *ninbuf,              dtype,
-                      outbuf,    recvcounts, displace, dtype,
-                      root_task, *comm ) ;
+  ierr = MPI_Gatherv( inbuf  , *ninbuf * *typesize  , MPI_CHAR ,
+               outbuf , recvcounts , displace, MPI_CHAR ,
+               root_task , *comm ) ;
 #ifndef MS_SUA
   if ( ierr != 0 ) fprintf(stderr,"%s %d MPI_Gatherv returns %d\n",__FILE__,__LINE__,ierr ) ;
 #endif
@@ -194,16 +185,14 @@ dst_on_comm ( int * Fcomm, int * typesize ,
       noutbuf_loc = noutbuf_loc + sendcounts[p] ;
 
       /* check for overflow: displace is the partial sum of sendcounts, which can overflow for large problems. */
-      /* it is sufficient to check displace[p] since it is greater than sendcounts[p] */
-      if ( (displace[p] < 0) || (noutbuf_loc < 0) )
-        {
+      if ( (displace[p] < 0) || (noutbuf_loc < 0) ) {
 #ifndef MS_SUA
-          fprintf(stderr,"%s %d buffer offset overflow!!\n",__FILE__,__LINE__) ;
-          fprintf(stderr," ---> p = %d,\n ---> displace[%d] = %d,\n ---> noutbuf_loc = %d,\n ---> typesize = %d\n",
-                  p, p, displace[p], noutbuf_loc, *typesize);
+        fprintf(stderr,"%s %d buffer offset overflow!!\n",__FILE__,__LINE__) ;
+        fprintf(stderr," ---> p = %d,\n ---> displace[%d] = %d,\n ---> noutbuf_loc = %d,\n ---> typesize = %d\n",
+                p, p, displace[p], noutbuf_loc, *typesize);
 #endif
-          MPI_Abort(MPI_COMM_WORLD,1) ;
-        }
+        MPI_Abort(MPI_COMM_WORLD,1) ;
+      }
     }
   }
 
@@ -211,12 +200,17 @@ dst_on_comm ( int * Fcomm, int * typesize ,
   ierr = MPI_Type_match_size (MPI_TYPECLASS_REAL, *typesize, &dtype);
   if (MPI_SUCCESS != ierr) {
     ierr = MPI_Type_match_size (MPI_TYPECLASS_INTEGER, *typesize, &dtype);
-  }
-  if (MPI_SUCCESS != ierr) {
+    if (MPI_SUCCESS != ierr) {
+      if (1 == *typesize) {
+        dtype = MPI_CHAR;
+      }
+      else {
 #ifndef MS_SUA
-    fprintf(stderr,"%s %d FATAL ERROR: unhandled typesize = %d!!\n", __FILE__,__LINE__,*typesize) ;
+        fprintf(stderr,"%s %d FATAL ERROR: unhandled typesize = %d!!\n", __FILE__,__LINE__,*typesize) ;
 #endif
-    MPI_Abort(MPI_COMM_WORLD,1) ;
+        MPI_Abort(MPI_COMM_WORLD,1) ;
+      }
+    }
   }
 
   MPI_Scatterv( inbuf,     sendcounts,  displace, dtype,