diff --git a/oscar/SleepLib/event.cpp b/oscar/SleepLib/event.cpp
index a90bdbb1..6eda1143 100644
--- a/oscar/SleepLib/event.cpp
+++ b/oscar/SleepLib/event.cpp
@@ -1,4 +1,4 @@
-/* SleepLib Event Class Implementation
+/* SleepLib Event Class Implementation
  *
  * Copyright (c) 2011-2018 Mark Watkins <mark@jedimark.net>
  *
@@ -85,12 +85,12 @@ void EventList::AddEvent(qint64 time, EventStoreType data)
     if (m_first > time) {
         // Crud.. Update all the previous records
         // This really shouldn't happen.
-        qDebug() << "Unordered time detected in AddEvent().";
+        qDebug() << "Unordered time detected in AddEvent()" << m_count << m_first << time << data;
 
         qint32 delta = (m_first - time);
 
         for (quint32 i = 0; i < m_count; ++i) {
-            m_time[i] -= delta;
+            m_time[i] += delta;
         }
 
         m_first = time;
diff --git a/oscar/SleepLib/loader_plugins/prs1_loader.cpp b/oscar/SleepLib/loader_plugins/prs1_loader.cpp
index 8efec2f8..63a432ed 100644
--- a/oscar/SleepLib/loader_plugins/prs1_loader.cpp
+++ b/oscar/SleepLib/loader_plugins/prs1_loader.cpp
@@ -3072,7 +3072,7 @@ bool PRS1DataChunk::ParseEventsF0(CPAPMode mode)
 
             pos += 2;
             data1 = buffer[pos++];
-            this->AddEvent(new PRS1UnknownValueEvent(code, t - data1, data0));
+            this->AddEvent(new PRS1UnknownValueEvent(code, t - data1, data0));  // TODO: start time should probably match PB below
             break;
 
         case 0x0f: // Cheyne Stokes Respiration
@@ -3083,7 +3083,11 @@ bool PRS1DataChunk::ParseEventsF0(CPAPMode mode)
             }
             pos += 2;
             data1 = buffer[pos++];
-            this->AddEvent(new PRS1PeriodicBreathingEvent(t - data1, data0));
+            if (this->familyVersion == 2 || this->familyVersion == 3) {
+                this->AddEvent(new PRS1PeriodicBreathingEvent(t - data1 - data0, data0));  // PB event appears data1 seconds after conclusion
+            } else {
+                this->AddEvent(new PRS1PeriodicBreathingEvent(t - data1, data0));  // TODO: this should probably be the same as F0V23, but it hasn't been tested
+            }
             break;
 
         case 0x10: // Large Leak
@@ -3094,7 +3098,7 @@ bool PRS1DataChunk::ParseEventsF0(CPAPMode mode)
             }
             pos += 2;
             data1 = buffer[pos++];
-            this->AddEvent(new PRS1LargeLeakEvent(t - data1, data0));
+            this->AddEvent(new PRS1LargeLeakEvent(t - data1, data0));  // TODO: start time should probably match PB above
             break;
 
         case 0x11: // Leak Rate & Snore Graphs