diff --git a/java/com.sap.sailing.domain.test/src/com/sap/sailing/domain/test/TrackTest.java b/java/com.sap.sailing.domain.test/src/com/sap/sailing/domain/test/TrackTest.java
index d2b4ff0c65b..b6d5c81d38d 100755
--- a/java/com.sap.sailing.domain.test/src/com/sap/sailing/domain/test/TrackTest.java
+++ b/java/com.sap.sailing.domain.test/src/com/sap/sailing/domain/test/TrackTest.java
@@ -56,7 +56,6 @@ import com.sap.sse.common.TimePoint;
 import com.sap.sse.common.Util;
 import com.sap.sse.common.Util.Pair;
 import com.sap.sse.common.impl.MillisecondsTimePoint;
-import com.sap.sse.concurrent.LockUtil;
 
 public class TrackTest {
     private DynamicGPSFixTrack<Boat, GPSFixMoving> track;
@@ -279,7 +278,6 @@ public class TrackTest {
 
                     @Override
                     public void gpsFixReceived(GPSFixMoving fix, Object item, boolean firstFixInTrack) {
-                        LockUtil.lockForWrite(getLock());
                         try {
                             // trigger the barrier after having acquired the cache write lock; this is what the
                             // super.gpsFixReceived(...) method will also do (reentrantly), but this way we can
@@ -289,8 +287,6 @@ public class TrackTest {
                             gpsFixReceivedDone.await();
                         } catch (InterruptedException | BrokenBarrierException e) {
                             throw new RuntimeException(e);
-                        } finally {
-                            LockUtil.unlockAfterWrite(getLock());
                         }
                     }
                 };
diff --git a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/MaxSpeedCache.java b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/MaxSpeedCache.java
index d959481aa66..8a9ff953a49 100755
--- a/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/MaxSpeedCache.java
+++ b/java/com.sap.sailing.domain/src/com/sap/sailing/domain/tracking/impl/MaxSpeedCache.java
@@ -180,8 +180,16 @@ public class MaxSpeedCache<ItemType, FixType extends GPSFix> implements GPSTrack
         if (!to.before(from)) {
             result = cacheLookup(from, to);
             if (result == null) {
-                result = computeMaxSpeed(from, to);
-                cache(from, to, result);
+//                LockUtil.lockForWrite(lock);
+//                try {
+                    // need to run both, the re-calculation as well as the caching, under the write lock because otherwise
+                    // an invocation of gpsFixReceived(...) may cut in between, obtain the write lock and perform invalidations
+                    // that would have needed to invalidate the value recalculated.
+                    result = computeMaxSpeed(from, to);
+                    cache(from, to, result);
+//                } finally {
+//                    LockUtil.unlockAfterWrite(lock);
+//                }
             }
         }
         return result;