diff --git a/html/planeObject.js b/html/planeObject.js
index 47d2aa5..782a2a7 100644
--- a/html/planeObject.js
+++ b/html/planeObject.js
@@ -3020,8 +3020,13 @@ function normalizeTraceStamps(data) {
     }
     let trace = data.trace;
     let last = 0;
+    let negOffsetWarned = 0;
     for (let i = 0; i < trace.length; i++) {
         let point = trace[i];
+        if (point[0] < 0 && !negOffsetWarned) {
+            negOffsetWarned = 1;
+            console.log('negative offset in trace');
+        }
         point[0] += data.timestamp;
         if (point[0] >= last) {
             last = point[0];
diff --git a/html/script.js b/html/script.js
index 504b3f7..6e6355d 100644
--- a/html/script.js
+++ b/html/script.js
@@ -6660,8 +6660,9 @@ function legShift(offset, plane) {
         if (traceOpts.startStamp != null && timestamp < traceOpts.startStamp) {
             continue;
         }
-        if (traceOpts.endStamp != null && timestamp > traceOpts.endStamp)
+        if (traceOpts.endStamp != null && timestamp > traceOpts.endStamp) {
             break;
+        }
         if (legStart == null) {
             legStart = i;
             i++;