diff --git a/src/cipsi/pt2_stoch_routines.irp.f b/src/cipsi/pt2_stoch_routines.irp.f
index e9a1f724..afa7a636 100644
--- a/src/cipsi/pt2_stoch_routines.irp.f
+++ b/src/cipsi/pt2_stoch_routines.irp.f
@@ -519,7 +519,7 @@ subroutine pt2_collector(zmq_socket_pull, E, relative_error, pt2, error, varianc
     else
       call pull_pt2_results(zmq_socket_pull, index, eI_task, vI_task, nI_task, task_id, n_tasks, b2)
       if (zmq_delete_tasks_async_send(zmq_to_qp_run_socket,task_id,n_tasks,sending) == -1) then
-          stop 'Unable to delete tasks'
+          stop 'PT2: Unable to delete tasks (send)'
       endif
       do i=1,n_tasks
         eI(1:N_states, index(i)) += eI_task(1:N_states,i)
@@ -533,7 +533,7 @@ subroutine pt2_collector(zmq_socket_pull, E, relative_error, pt2, error, varianc
         call add_to_selection_buffer(b, b2%det(1,1,i), b2%val(i))
       end do
       if (zmq_delete_tasks_async_recv(zmq_to_qp_run_socket,more,sending) == -1) then
-          stop 'Unable to delete tasks'
+          stop 'PT2: Unable to delete tasks (recv)'
       endif
     end if
   end do
diff --git a/src/cipsi/run_pt2_slave.irp.f b/src/cipsi/run_pt2_slave.irp.f
index b6545922..21def8f2 100644
--- a/src/cipsi/run_pt2_slave.irp.f
+++ b/src/cipsi/run_pt2_slave.irp.f
@@ -31,7 +31,7 @@ subroutine run_pt2_slave(thread,iproc,energy)
 
   double precision, intent(in)    :: energy(N_states_diag)
   integer,  intent(in)            :: thread, iproc
-  if (N_det > 1000000) then
+  if (N_det > nproc*(elec_alpha_num * (mo_num-elec_alpha_num))**2) then
     call run_pt2_slave_large(thread,iproc,energy)
   else
     call run_pt2_slave_small(thread,iproc,energy)
@@ -236,7 +236,7 @@ subroutine run_pt2_slave_large(thread,iproc,energy)
       call create_selection_buffer(bsize, bsize*2, b)
       buffer_ready = .True.
     else
-      ASSERT (N == b%N)
+      ASSERT (b%N == bsize)
     endif
 
     double precision :: time0, time1
diff --git a/src/davidson/davidson_parallel.irp.f b/src/davidson/davidson_parallel.irp.f
index c615fae7..9e4402f6 100644
--- a/src/davidson/davidson_parallel.irp.f
+++ b/src/davidson/davidson_parallel.irp.f
@@ -359,7 +359,7 @@ subroutine davidson_collector(zmq_to_qp_run_socket, zmq_socket_pull, v0, s0, sze
   do while (more == 1)
     call davidson_pull_results(zmq_socket_pull, v_t, s_t, imin, imax, task_id)
     if (zmq_delete_task_async_send(zmq_to_qp_run_socket,task_id,sending) == -1) then
-      stop 'Unable to delete task'
+      stop 'davidson: Unable to delete task (send)'
     endif
     do j=1,N_st
       do i=imin,imax
@@ -368,7 +368,7 @@ subroutine davidson_collector(zmq_to_qp_run_socket, zmq_socket_pull, v0, s0, sze
       enddo
     enddo
     if (zmq_delete_task_async_recv(zmq_to_qp_run_socket,more,sending) == -1) then
-      stop 'Unable to delete task'
+      stop 'davidson: Unable to delete task (recv)'
     endif
   end do
   deallocate(v_t,s_t)
diff --git a/src/zmq/utils.irp.f b/src/zmq/utils.irp.f
index 520be0d7..1205e09e 100644
--- a/src/zmq/utils.irp.f
+++ b/src/zmq/utils.irp.f
@@ -1127,6 +1127,7 @@ integer function zmq_delete_task_async_recv(zmq_to_qp_run_socket,more,sending)
   integer                        :: rc
   character*(512)                :: message
   character*(64) :: reply
+  zmq_delete_task_async_recv = 0
   if (.not.sending) return
   sending = .False.
   reply = ''
@@ -1136,6 +1137,7 @@ integer function zmq_delete_task_async_recv(zmq_to_qp_run_socket,more,sending)
   else if (reply(16:19) == 'done') then
     more = 0
   else
+    print *,  reply(1:rc)
     zmq_delete_task_async_recv = -1
     return
   endif