diff --git a/lib/dtscmeta.cpp b/lib/dtscmeta.cpp
index b9a5bccd..c3dfa4da 100644
--- a/lib/dtscmeta.cpp
+++ b/lib/dtscmeta.cpp
@@ -1258,7 +1258,7 @@ namespace DTSC {
     //update firstms
     firstms = keys[0].getTime();
     //delete any fragments no longer fully buffered
-    while (fragments[0].getNumber() < keys[0].getNumber()) {
+    while (fragments.size() && keys.size() && fragments[0].getNumber() < keys[0].getNumber()) {
       fragments.pop_front();
       fragInsertTime.pop_front();
       //and update the missed fragment counter
@@ -1658,8 +1658,8 @@ namespace DTSC {
     writePointer(p, "\340", 1);//Begin track object
     writePointer(p, "\000\011fragments\002", 12);
     writePointer(p, convertInt(fragments.size() * PACKED_FRAGMENT_SIZE), 4);
-    for (std::deque<Fragment>::iterator it = fragments.begin(); it != fragments.end(); it++) {
-      writePointer(p, it->getData(), PACKED_FRAGMENT_SIZE);
+    for (; firstFrag != fragments.end(); ++firstFrag) {
+      writePointer(p, firstFrag->getData(), PACKED_FRAGMENT_SIZE);
     }
     writePointer(p, "\000\004keys\002", 7);
     writePointer(p, convertInt(keys.size() * PACKED_KEY_SIZE), 4);