diff --git a/rs/java/android/renderscript/Allocation.java b/rs/java/android/renderscript/Allocation.java
index c2bab91..20b7ee7 100644
--- a/rs/java/android/renderscript/Allocation.java
+++ b/rs/java/android/renderscript/Allocation.java
@@ -776,10 +776,11 @@
         mRS.validate();
         int eSize = mType.mElement.getBytesSize();
         final byte[] data = fp.getData();
+        int data_length = fp.getPos();
 
-        int count = data.length / eSize;
-        if ((eSize * count) != data.length) {
-            throw new RSIllegalArgumentException("Field packer length " + data.length +
+        int count = data_length / eSize;
+        if ((eSize * count) != data_length) {
+            throw new RSIllegalArgumentException("Field packer length " + data_length +
                                                " not divisible by element size " + eSize + ".");
         }
         copy1DRangeFromUnchecked(xoff, count, data);
@@ -803,16 +804,17 @@
         }
 
         final byte[] data = fp.getData();
+        int data_length = fp.getPos();
         int eSize = mType.mElement.mElements[component_number].getBytesSize();
         eSize *= mType.mElement.mArraySizes[component_number];
 
-        if (data.length != eSize) {
-            throw new RSIllegalArgumentException("Field packer sizelength " + data.length +
+        if (data_length != eSize) {
+            throw new RSIllegalArgumentException("Field packer sizelength " + data_length +
                                                " does not match component size " + eSize + ".");
         }
 
         mRS.nAllocationElementData1D(getIDSafe(), xoff, mSelectedLOD,
-                                     component_number, data, data.length);
+                                     component_number, data, data_length);
     }
 
     private void data1DChecks(int off, int count, int len, int dataSize) {
diff --git a/rs/java/android/renderscript/FieldPacker.java b/rs/java/android/renderscript/FieldPacker.java
index 576a84d..dccc1ac 100644
--- a/rs/java/android/renderscript/FieldPacker.java
+++ b/rs/java/android/renderscript/FieldPacker.java
@@ -76,7 +76,7 @@
         mPos = 0;
     }
     public void reset(int i) {
-        if ((i < 0) || (i >= mLen)) {
+        if ((i < 0) || (i > mLen)) {
             throw new RSIllegalArgumentException("out of range argument: " + i);
         }
         mPos = i;
@@ -606,6 +606,15 @@
         return mData;
     }
 
+    /**
+     * Get the actual length used for the FieldPacker.
+     *
+     * @hide
+     */
+    public int getPos() {
+        return mPos;
+    }
+
     private final byte mData[];
     private int mPos;
     private int mLen;
diff --git a/rs/java/android/renderscript/ProgramVertexFixedFunction.java b/rs/java/android/renderscript/ProgramVertexFixedFunction.java
index a350154..7026597 100644
--- a/rs/java/android/renderscript/ProgramVertexFixedFunction.java
+++ b/rs/java/android/renderscript/ProgramVertexFixedFunction.java
@@ -249,6 +249,9 @@
             for(int i = 0; i < 16; i ++) {
                 mIOBuffer.addF32(m.mMat[i]);
             }
+            // Reset the buffer back to the end, since we want to flush all of
+            // the contents back (and not just what we wrote now).
+            mIOBuffer.reset(mIOBuffer.getData().length);
             mAlloc.setFromFieldPacker(0, mIOBuffer);
         }