diff --git a/endpoint.go b/endpoint.go
index 0c43277..d2bf69a 100644
--- a/endpoint.go
+++ b/endpoint.go
@@ -198,6 +198,8 @@ func (e *Endpoint) SetStateEx(newState EndpointState, takeMutex bool) {
 	} else {
 		e.listElement = newList.PushBack(e)
 	}
+
+	e.state = newState
 }
 
 func (e *Endpoint) SetState(newState EndpointState) {
@@ -217,6 +219,7 @@ func (e *Endpoint) Delay(addTime time.Duration) {
 
 		tm := time.Now().Add(addTime)
 		if e.delayUntil.Before(tm) {
+			log("ep", 5, "extending delay deadline for endpoint \"%v\" from %v to %v", e, e.delayUntil, tm)
 			e.delayUntil = tm
 		}
 	}
@@ -360,7 +363,9 @@ func (e *Endpoint) NoSuchLogin(login string) {
 
 // Exhausted gets called when an endpoint no longer has any valid logins and passwords,
 // thus it may be deleted.
-func (e *Endpoint) Exhausted() {	
+func (e *Endpoint) Exhausted() {
+	e.TakeMutex()
+	defer e.ReleaseMutex()
 	e.Delete()
 }
 
@@ -389,7 +394,11 @@ func GetDelayedEndpoint() (e *Endpoint, waitTime time.Duration) {
 		}
 	}
 
-	return nil, minWaitTime.Sub(currentTime)
+	if minWaitTime.Before(currentTime) {
+		return nil, 0
+	} else {
+		return nil, minWaitTime.Sub(currentTime)
+	}
 }
 
 func (e *Endpoint) TakeMutex() {
diff --git a/service.go b/service.go
index 74359e7..2b49e55 100644
--- a/service.go
+++ b/service.go
@@ -23,6 +23,6 @@ func TryLogin(task *Task, conn *Connection) (res bool, err error) {
 		}
 	}()
 
-	res, err = NewWinbox(task, conn).TryLogin()
+	res, err = NewLegacyWinbox(task, conn).TryLogin()
 	return res, err
 }
diff --git a/task.go b/task.go
index d88eb2e..8a33590 100644
--- a/task.go
+++ b/task.go
@@ -177,7 +177,11 @@ func GetDeferredTask() (task *Task, waitTime time.Duration) {
 		}
 	}
 
-	return nil, minWaitTime.Sub(currentTime)
+	if minWaitTime.Before(currentTime) {
+		return nil, 0
+	} else {
+		return nil, minWaitTime.Sub(currentTime)
+	}
 }
 
 // FetchTaskComponents returns all components needed to build a Task.
@@ -249,6 +253,10 @@ func CreateTask(threadIdx int) (task *Task, delay time.Duration) {
 		}
 	}
 
+	if getParamInt("max-aps") > 0 {
+		ep.Delay(time.Duration(float64(1000.0) / float64(getParamInt("max-aps")) * float64(time.Millisecond)))
+	}
+
 	t := Task{e: ep, login: login, password: password, thread: threadIdx}
 	log("task", 4, "new task: %v", &t)
 
diff --git a/thread.go b/thread.go
index b780bf9..5b41ae9 100644
--- a/thread.go
+++ b/thread.go
@@ -68,9 +68,11 @@ func threadWork(threadIdx int) bool {
 			log("thread", 3, "no work currently available, sleeping for %v in thread %v", delay, threadIdx)
 			time.Sleep(delay)
 			return true
-		} else {
+		} else if delay == 0 {
 			log("thread", 2, "no more work for thread %v", threadIdx)
 			return false
+		} else {
+			panic("negative task creation delay: " + delay.String())
 		}
 	}