diff --git a/sleepyhead/SleepLib/loader_plugins/prs1_loader.cpp b/sleepyhead/SleepLib/loader_plugins/prs1_loader.cpp
index ccce8aba..14b1eb4e 100644
--- a/sleepyhead/SleepLib/loader_plugins/prs1_loader.cpp
+++ b/sleepyhead/SleepLib/loader_plugins/prs1_loader.cpp
@@ -3167,9 +3167,9 @@ void PRS1Import::run()
             session->UpdateSummaries();
 
             // Save is not threadsafe
-          //  loader->saveMutex.lock();
+            loader->saveMutex.lock();
             session->Store(mach->getDataPath());
-           // loader->saveMutex.unlock();
+            loader->saveMutex.unlock();
 
             // Unload them from memory
             session->TrashEvents();
diff --git a/sleepyhead/SleepLib/session.cpp b/sleepyhead/SleepLib/session.cpp
index 187d9e2c..148faff5 100644
--- a/sleepyhead/SleepLib/session.cpp
+++ b/sleepyhead/SleepLib/session.cpp
@@ -1188,6 +1188,10 @@ EventDataType Session::SearchValue(ChannelID code, qint64 time, bool square)
                     qint64 tt = time - el->first();
 
                     double i = tt / el->rate();
+                    if (i> cnt) {
+                        qWarning() << "Session" << session() << "time bounds are broken.. There is a fault in the" << machine()->loaderName().toLocal8Bit.data() << "loader";
+                        return 0;
+                    }
 
                     int i1 = int(floor(i));
                     int i2 = int(ceil(i));