diff --git a/amitools/vamos/lib/dos/Process.py b/amitools/vamos/lib/dos/Process.py
index fa0af7d7..f259c7cd 100644
--- a/amitools/vamos/lib/dos/Process.py
+++ b/amitools/vamos/lib/dos/Process.py
@@ -198,7 +198,7 @@ def _init_task(self, machine):
         start_regs = self._get_start_regs()
         return_regs = [REG_D0]
         self.task = NativeTask(
-            name, machine, init_pc, self.stack, start_regs, return_regs
+            name, machine, self.stack, init_pc, start_regs, return_regs
         )
         # store back ref to process
         self.task.process = self
diff --git a/amitools/vamos/main.py b/amitools/vamos/main.py
index df260fc5..0a47fd5c 100644
--- a/amitools/vamos/main.py
+++ b/amitools/vamos/main.py
@@ -87,7 +87,7 @@ def main(cfg_files=None, args=None, cfg_dict=None, profile=False):
         def runner(*args, **kw_args):
             task = scheduler.get_cur_task()
             if task:
-                return task.run(*args, **kw_args)
+                return task.sub_run(*args, **kw_args)
             else:
                 return default_runtime.run(*args, **kw_args)
 
diff --git a/amitools/vamos/schedule/scheduler.py b/amitools/vamos/schedule/scheduler.py
index 433b579d..6d751c9a 100644
--- a/amitools/vamos/schedule/scheduler.py
+++ b/amitools/vamos/schedule/scheduler.py
@@ -55,8 +55,11 @@ def schedule(self):
         # main loop
         while True:
             log_schedule.debug(
-                "schedule: current %s added %s ready %s waiting %s",
+                "schedule: current %s",
                 self.cur_task,
+            )
+            log_schedule.debug(
+                "schedule: added %s ready %s waiting %s",
                 self.added_tasks,
                 self.ready_tasks,
                 self.waiting_tasks,
@@ -134,7 +137,7 @@ def _find_run_task(self):
         # keep current task
         task = self.cur_task
         log_schedule.debug("take: current task %s", task.name)
-        if task.get_state() == TaskState.TS_READY:
+        if task.get_state() in (TaskState.TS_READY, TaskState.TS_RUN):
             return task
 
     def _make_current(self, task):
diff --git a/amitools/vamos/schedule/task.py b/amitools/vamos/schedule/task.py
index a357a8e6..9e9b09e6 100644
--- a/amitools/vamos/schedule/task.py
+++ b/amitools/vamos/schedule/task.py
@@ -197,7 +197,7 @@ def __repr__(self):
 
     def start(self):
         pc = self.init_pc
-        sp = self.get_init_sp()
+        sp = self.stack.get_initial_sp()
         set_regs = self.start_regs
         get_regs = self.return_regs
         log_schedule.debug("%s: start native code. pc=%06x sp=%06x", self.name, pc, sp)