diff --git a/src/MS/data.cpp b/src/MS/data.cpp
index 6313663b..8254dca3 100644
--- a/src/MS/data.cpp
+++ b/src/MS/data.cpp
@@ -46,7 +46,7 @@ int Data::TileSize = 120;
 int Data::Nt= 6; 
 char *Data::SkyModel=NULL;
 char *Data::Clusters=NULL;
-int Data::format=0; /* old LSM */
+int Data::format=1; /* defaut is LSM with 3rd order spectra */
 double Data::nulow=2.0;
 double Data::nuhigh=30.0;
 
diff --git a/src/buildsky/create_clusters.py b/src/buildsky/create_clusters.py
index 5a7ca51b..fe9645e0 100755
--- a/src/buildsky/create_clusters.py
+++ b/src/buildsky/create_clusters.py
@@ -206,7 +206,7 @@ def radec_to_lm_SIN(ra0,dec0,ra,dec):
 
 
 #### main clustering routine : Q clusters
-def cluster_this(skymodel,Q,outfile,max_iterations):
+def cluster_this(skymodel,Q,outfile,max_iterations=5):
    SKY=read_lsm_sky(skymodel)
    K=len(SKY)
 
@@ -243,7 +243,7 @@ def cluster_this(skymodel,Q,outfile,max_iterations):
       C[ci,0]=X[sImax,0]
       C[ci,1]=X[sImax,1]
       sItmp[sImax]=0.0
-   #print C
+   #print(C)
    # calculate weights
 
    # arrays to store which cluster each source belongs to
@@ -264,7 +264,7 @@ def cluster_this(skymodel,Q,outfile,max_iterations):
           mra=X[ci,0]
           mdec=X[ci,1]
           closest=find_closest(mra,mdec,C,Ccos,Csin)
-          #print "src %d closest %d"%(ci,closest)
+          #print("src %d closest %d"%(ci,closest))
           CL[ci]=closest
           # add this source to dict
           if closest in D:
@@ -272,7 +272,7 @@ def cluster_this(skymodel,Q,outfile,max_iterations):
           else:
               D[closest]=list()
               D[closest].append(ci)
-      #print D
+      #print(D)
       
       # check to see also if source assignment changes
       if numpy.sum(CL-CLold)==0:
@@ -341,6 +341,8 @@ def cluster_this(skymodel,Q,outfile,max_iterations):
 
   if opts.skymodel and opts.clusters and opts.outfile and opts.iterations:
     cluster_this(opts.skymodel,opts.clusters,opts.outfile,opts.iterations)
+  elif opts.skymodel and opts.clusters and opts.outfile:
+    cluster_this(opts.skymodel,opts.clusters,opts.outfile)
   else:
    parser.print_help()
   exit()
diff --git a/src/lib/Dirac/lmfit.c b/src/lib/Dirac/lmfit.c
index dc68961b..2bfaae6f 100644
--- a/src/lib/Dirac/lmfit.c
+++ b/src/lib/Dirac/lmfit.c
@@ -1183,7 +1183,7 @@ bfgsfit_visibilities(double *u, double *v, double *w, double *x, int N,
   lmdata.Nt=64; /* increase threads for MIC */
 #endif
   /* use LBFGS */
-   if (solver_mode==2 || solver_mode==3) {
+   if (solver_mode==SM_RLM_RLBFGS || solver_mode==SM_OSLM_OSRLM_RLBFGS || solver_mode==SM_RTR_OSRLM_RLBFGS || solver_mode==SM_NSD_RLBFGS ) {
     lmdata.robust_nu=mean_nu;
     lbfgs_fit_robust_wrapper(p, x, m, n, max_lbfgs, lbfgs_m, gpu_threads, (void*)&lmdata); 
    } else {
diff --git a/src/lib/Dirac/lmfit_cuda.c b/src/lib/Dirac/lmfit_cuda.c
index b41052b7..65e4637b 100644
--- a/src/lib/Dirac/lmfit_cuda.c
+++ b/src/lib/Dirac/lmfit_cuda.c
@@ -1421,7 +1421,7 @@ bfgsfit_visibilities_gpu(double *u, double *v, double *w, double *x, int N,
 
   if (max_lbfgs>0) {
    /* use LBFGS */
-   if (solver_mode==2 || solver_mode==3) {
+   if (solver_mode==SM_RLM_RLBFGS || solver_mode==SM_OSLM_OSRLM_RLBFGS || solver_mode==SM_RTR_OSRLM_RLBFGS || solver_mode==SM_NSD_RLBFGS) {
     lmdata.robust_nu=mean_nu;
     lbfgs_fit_robust_cuda(p, x, m, n, max_lbfgs, lbfgs_m, gpu_threads, (void*)&lmdata);
    } else {
diff --git a/src/lib/Dirac/load_balance.c b/src/lib/Dirac/load_balance.c
index 90361c90..fb3b8027 100644
--- a/src/lib/Dirac/load_balance.c
+++ b/src/lib/Dirac/load_balance.c
@@ -64,6 +64,7 @@ destroy_task_hist(taskhist *th) {
    in such a way to allow load balancing */
 int
 select_work_gpu(int max_gpu, taskhist *th) {
+  if (!max_gpu) return 0; /* no need to spend time if only one GPU is available */
 #ifdef MPI_BUILD
   int rank;
   MPI_Comm_rank(MPI_COMM_WORLD, &rank);