diff --git a/lib/procs.cpp b/lib/procs.cpp
index f136b92a..3fb7212c 100644
--- a/lib/procs.cpp
+++ b/lib/procs.cpp
@@ -444,6 +444,18 @@ int Util::Procs::Count() {
 /// Returns true if a process with this PID is currently active.
 bool Util::Procs::isActive(pid_t name) {
   tthread::lock_guard<tthread::mutex> guard(plistMutex);
-  return (plist.count(name) == 1) && (kill(name, 0) == 0);
+  return (kill(name, 0) == 0);
+}
+
+/// Forget about the given PID, keeping it running on shutdown.
+void Util::Procs::forget(pid_t pid) {
+  tthread::lock_guard<tthread::mutex> guard(plistMutex);
+  plist.erase(pid);
+}
+
+/// Remember the given PID, killing it on shutdown.
+void Util::Procs::remember(pid_t pid) {
+  tthread::lock_guard<tthread::mutex> guard(plistMutex);
+  plist.insert(pid);
 }
 
diff --git a/lib/procs.h b/lib/procs.h
index 2c07cda8..667f570b 100644
--- a/lib/procs.h
+++ b/lib/procs.h
@@ -38,6 +38,8 @@ namespace Util {
       static int Count();
       static bool isActive(pid_t name);
       static bool isRunning(pid_t pid);
+      static void forget(pid_t pid);
+      static void remember(pid_t pid);
       static std::set<int> socketList; ///< Holds sockets that should be closed before forking
   };
 }
diff --git a/src/input/input.cpp b/src/input/input.cpp
index 0222dbdd..607f44ee 100644
--- a/src/input/input.cpp
+++ b/src/input/input.cpp
@@ -142,6 +142,17 @@ namespace Mist {
     return 0;
   }
 
+  /// Default crash handler, cleans up Pull semaphore on crashes
+  void Input::onCrash(){
+    if (streamName.size() && !needsLock()) {
+      //we have a Pull semaphore to clean up, do it
+      IPC::semaphore pullLock;
+      pullLock.open(std::string("/MstPull_" + streamName).c_str(), O_CREAT | O_RDWR, ACCESSPERMS, 1);
+      pullLock.close();
+      pullLock.unlink();
+    }
+  }
+
   void Input::convert() {
     //check filename for no -
     if (config->getString("output") != "-") {
@@ -262,12 +273,18 @@ namespace Mist {
   }
 
   /// Main loop for stream-style inputs.
-  /// This loop will start the buffer without resume support, and then repeatedly call ..... followed by ....
+  /// This loop will do the following, in order:
+  /// - exit if another stream() input is already open for this streamname
+  /// - start a buffer in push mode
+  /// - connect to it
+  /// - run parseStreamHeader
+  /// - if there are tracks, register as a non-viewer on the user page of the buffer
+  /// - call getNext() in a loop, buffering packets
   void Input::stream(){
     IPC::semaphore pullLock;
     pullLock.open(std::string("/MstPull_" + streamName).c_str(), O_CREAT | O_RDWR, ACCESSPERMS, 1);
     if (!pullLock.tryWait()){
-      DEBUG_MSG(DLVL_DEVEL, "A pull process for stream %s is already running", streamName.c_str());
+      WARN_MSG("A pull process for stream %s is already running", streamName.c_str());
       pullLock.close();
       return;
     }
diff --git a/src/input/input.h b/src/input/input.h
index 66580bb1..f80ac6c7 100644
--- a/src/input/input.h
+++ b/src/input/input.h
@@ -20,7 +20,7 @@ namespace Mist {
     public:
       Input(Util::Config * cfg);
       virtual int run();
-      virtual void onCrash(){}
+      virtual void onCrash();
       virtual void argumentsParsed(){}
       virtual ~Input() {};
 
diff --git a/src/output/output.cpp b/src/output/output.cpp
index 064270dc..56b07757 100644
--- a/src/output/output.cpp
+++ b/src/output/output.cpp
@@ -547,7 +547,10 @@ namespace Mist{
     }
     return highest;
   }
-  
+ 
+  /// Loads the page for the given trackId and keyNum into memory.
+  /// Overwrites any existing page for the same trackId.
+  /// Automatically calls thisPacket.null() if necessary.
   void Output::loadPageForKey(long unsigned int trackId, long long int keyNum){
     if (!myMeta.tracks.count(trackId) || !myMeta.tracks[trackId].keys.size()){
       WARN_MSG("Load for track %lu key %lld aborted - track is empty", trackId, keyNum);
@@ -598,6 +601,10 @@ namespace Mist{
     if (currKeyOpen.count(trackId) && currKeyOpen[trackId] == (unsigned int)pageNum){
       return;
     }
+    //If we're loading the track thisPacket is on, null it to prevent accesses.
+    if (thisPacket && thisPacket.getTrackId() == trackId){
+      thisPacket.null();
+    }
     char id[NAME_BUFFER_SIZE];
     snprintf(id, NAME_BUFFER_SIZE, SHM_TRACK_DATA, streamName.c_str(), trackId, pageNum);
     nProxy.curPage[trackId].init(id, DEFAULT_DATA_PAGE_SIZE);
@@ -951,7 +958,7 @@ namespace Mist{
   }
  
   ///Attempts to prepare a new packet for output.
-  ///If thisPacket evaluates to false, playback has completed.
+  ///If it returns true and thisPacket evaluates to false, playback has completed.
   ///Could be called repeatedly in a loop if you really really want a new packet.
   /// \returns true if thisPacket was filled with the next packet.
   /// \returns false if we could not reliably determine the next packet yet.
@@ -1009,7 +1016,9 @@ namespace Mist{
     //if we're going to read past the end of the data page, load the next page
     //this only happens for VoD
     if (nxt.offset >= nProxy.curPage[nxt.tid].len){
-      nxtKeyNum[nxt.tid] = getKeyForTime(nxt.tid, thisPacket.getTime());
+      if (thisPacket){
+        nxtKeyNum[nxt.tid] = getKeyForTime(nxt.tid, thisPacket.getTime());
+      }
       loadPageForKey(nxt.tid, ++nxtKeyNum[nxt.tid]);
       nxt.offset = 0;
       if (nProxy.curPage.count(nxt.tid) && nProxy.curPage[nxt.tid].mapped){
@@ -1022,7 +1031,6 @@ namespace Mist{
           buffer.insert(nxt);
         }
       }else{
-        thisPacket.null();
         dropTrack(nxt.tid, "page load failure", true);
       }
       return false;
@@ -1063,7 +1071,6 @@ namespace Mist{
       //The next key showed up on another page!
       //We've simply reached the end of the page. Load the next key = next page.
       loadPageForKey(nxt.tid, ++nxtKeyNum[nxt.tid]);
-      thisPacket.null();
       nxt.offset = 0;
       if (nProxy.curPage.count(nxt.tid) && nProxy.curPage[nxt.tid].mapped){
         unsigned long long nextTime = getDTSCTime(nProxy.curPage[nxt.tid].mapped, nxt.offset);
diff --git a/src/output/output.h b/src/output/output.h
index a45bba37..405b248f 100644
--- a/src/output/output.h
+++ b/src/output/output.h
@@ -61,6 +61,8 @@ namespace Mist {
       uint32_t currTrackCount() const;
       virtual bool isReadyForPlay();
       //virtuals. The optional virtuals have default implementations that do as little as possible.
+      /// This function is called whenever a packet is ready for sending.
+      /// Inside it, thisPacket is guaranteed to contain a valid packet.
       virtual void sendNext() {}//REQUIRED! Others are optional.
       bool prepareNext();
       virtual void dropTrack(uint32_t trackId, std::string reason, bool probablyBad = true);
diff --git a/src/output/output_rtmp.cpp b/src/output/output_rtmp.cpp
index a69d0be5..f5179fe5 100644
--- a/src/output/output_rtmp.cpp
+++ b/src/output/output_rtmp.cpp
@@ -257,7 +257,7 @@ namespace Mist {
       // erase &
       pos = nextpos + 1;
     }
-    if (trackSwitch){
+    if (trackSwitch && thisPacket){
       seek(thisPacket.getTime());
     }
   }