diff --git a/src/xschem.tcl b/src/xschem.tcl
index c05f4973..b667872a 100644
--- a/src/xschem.tcl
+++ b/src/xschem.tcl
@@ -1772,11 +1772,6 @@ proc simulate {{callback {}}} {
     set cmd [subst -nobackslashes $sim($tool,$def,cmd)]
     set save [pwd]
     cd $netlist_dir
-    if {[info exists has_x]} {
-      set button_path [xschem get top_path].menubar.simulate
-      $button_path configure -bg yellow
-      set tctx::[xschem get current_win_path]_simulate yellow
-    }
     if {$OS == "Windows"} {
       # $cmd cannot be surrounded by {} as exec will change forward slash to backward slash
       set_simulate_button list [xschem get top_path] [xschem get current_win_path]
@@ -1801,7 +1796,12 @@ proc simulate {{callback {}}} {
       "
       # puts $cmd
       set id [eval $fg $st $cmd]
-      if {[info exists has_x]} {set tctx::[xschem get current_win_path]_simulate_id $id}
+      if {[info exists has_x] && $id >= 0} {
+        set tctx::[xschem get current_win_path]_simulate_id $id
+        set button_path [xschem get top_path].menubar.simulate
+        $button_path configure -bg yellow
+        set tctx::[xschem get current_win_path]_simulate yellow
+      }
       puts "Simulation started: execution ID: $id"
     }
     cd $save
diff --git a/xschem_library/examples/poweramp.sch b/xschem_library/examples/poweramp.sch
index 4ad3b99c..81714cad 100644
--- a/xschem_library/examples/poweramp.sch
+++ b/xschem_library/examples/poweramp.sch
@@ -347,18 +347,8 @@ vvss vss 0 dc 0
 ** SPICE models for active devices and put them  into the below 
 ** referenced file in simulation directory.
 .include \\"models_poweramp.txt\\"
-.control
-save all
-op
-write poweramp_op.raw
-tran  8e-7 0.07 uic
-* .FOUR 20k v(outm,outp)
-* .probe i(*) 
-plot outp outm
-save p(r*) p(v*)
-write poweramp.raw
-quit 0
-.endc
+.save all
+.tran  8e-7 0.07 uic
 "}
 C {simulator_commands.sym} 1020 -870 0 0 {name=COMMANDS1
 simulator=xyce