diff --git a/Core/CoreTiming.cpp b/Core/CoreTiming.cpp
index f4c3868498..e49283cf65 100644
--- a/Core/CoreTiming.cpp
+++ b/Core/CoreTiming.cpp
@@ -71,7 +71,7 @@ Event *eventPool = 0;
 Event *eventTsPool = 0;
 int allocatedTsEvents = 0;
 // Optimization to skip MoveEvents when possible.
-volatile u32 hasTsEvents = false;
+volatile u32 hasTsEvents = 0;
 
 // Downcount has been moved to currentMIPS, to save a couple of clocks in every ARM JIT block
 // as we can already reach that structure through a register.
diff --git a/Core/HW/AsyncIOManager.cpp b/Core/HW/AsyncIOManager.cpp
index 3ff26be160..89dfaf6481 100644
--- a/Core/HW/AsyncIOManager.cpp
+++ b/Core/HW/AsyncIOManager.cpp
@@ -32,9 +32,11 @@ bool AsyncIOManager::HasOperation(u32 handle) {
 }
 
 void AsyncIOManager::ScheduleOperation(AsyncIOEvent ev) {
-	lock_guard guard(resultsLock_);
-	if (!resultsPending_.insert(ev.handle).second) {
-		ERROR_LOG_REPORT(SCEIO, "Scheduling operation for file %d while one is pending (type %d)", ev.handle, ev.type);
+	{
+		lock_guard guard(resultsLock_);
+		if (!resultsPending_.insert(ev.handle).second) {
+			ERROR_LOG_REPORT(SCEIO, "Scheduling operation for file %d while one is pending (type %d)", ev.handle, ev.type);
+		}
 	}
 	ScheduleEvent(ev);
 }
diff --git a/Core/System.cpp b/Core/System.cpp
index 31b2c90157..5b421e1415 100644
--- a/Core/System.cpp
+++ b/Core/System.cpp
@@ -76,6 +76,7 @@ GlobalUIState globalUIState;
 static CoreParameter coreParameter;
 static PSPMixer *mixer;
 static std::thread *cpuThread = NULL;
+static std::thread::id cpuThreadID;
 static recursive_mutex cpuThreadLock;
 static condition_variable cpuThreadCond;
 static condition_variable cpuThreadReplyCond;
@@ -108,7 +109,7 @@ void Audio_Init() {
 
 bool IsOnSeparateCPUThread() {
 	if (cpuThread != NULL) {
-		return cpuThread->get_id() == std::this_thread::get_id();
+		return cpuThreadID == std::this_thread::get_id();
 	} else {
 		return false;
 	}
@@ -336,6 +337,7 @@ bool PSP_InitStart(const CoreParameter &coreParam, std::string *error_string) {
 		XSetThreadProcessor(cpuThread->native_handle(), 2);
 		ResumeThread(cpuThread->native_handle());
 #endif
+		cpuThreadID = cpuThread->get_id();
 		cpuThread->detach();
 	} else {
 		CPU_Init();
@@ -411,6 +413,7 @@ void PSP_Shutdown() {
 		CPU_WaitStatus(cpuThreadReplyCond, &CPU_IsShutdown);
 		delete cpuThread;
 		cpuThread = 0;
+		cpuThreadID = std::thread::id();
 	} else {
 		CPU_Shutdown();
 	}
diff --git a/Core/ThreadEventQueue.h b/Core/ThreadEventQueue.h
index f18a2df4f1..3fdc0d043a 100644
--- a/Core/ThreadEventQueue.h
+++ b/Core/ThreadEventQueue.h
@@ -75,6 +75,10 @@ struct ThreadEventQueue : public B {
 		eventsHaveRun_ = true;
 
 		do {
+			if (!HasEvents()) {
+				eventsWait_.wait(eventsLock_);
+			}
+
 			for (Event ev = GetNextEvent(); EventType(ev) != EVENT_INVALID; ev = GetNextEvent()) {
 				eventsLock_.unlock();
 				switch (EventType(ev)) {
@@ -96,11 +100,6 @@ struct ThreadEventQueue : public B {
 			if (ShouldExitEventLoop() || !threadEnabled_) {
 				break;
 			}
-
-			// coreState changes won't wake us, so recheck periodically.
-			if (!HasEvents()) {
-				eventsWait_.wait(eventsLock_);
-			}
 		} while (CoreTiming::GetTicks() < globalticks);
 
 		// This will force the waiter to check coreState, even if we didn't actually drain.
@@ -113,6 +112,22 @@ struct ThreadEventQueue : public B {
 		eventsHaveRun_ = false;
 	}
 
+	inline bool ShouldSyncThread(bool force) {
+		if (!HasEvents())
+			return false;
+		if (coreState != CORE_RUNNING && !force)
+			return false;
+
+		// Don't run if it's not running, but wait for startup.
+		if (!eventsRunning_) {
+			if (eventsHaveRun_ || coreState == CORE_ERROR || coreState == CORE_POWERDOWN) {
+				return false;
+			}
+		}
+
+		return true;
+	}
+
 	// Force ignores coreState.
 	void SyncThread(bool force = false) {
 		if (!threadEnabled_) {
@@ -123,7 +138,7 @@ struct ThreadEventQueue : public B {
 		// While processing the last event, HasEvents() will be false even while not done.
 		// So we schedule a nothing event and wait for that to finish.
 		ScheduleEvent(EVENT_SYNC);
-		while (HasEvents() && (eventsRunning_ || !eventsHaveRun_) && (force || coreState == CORE_RUNNING)) {
+		while (ShouldSyncThread(force)) {
 			eventsDrain_.wait(eventsLock_);
 		}
 	}