diff --git a/src/java/org/lwjgl/test/mapped/MappedObjectTests1.java b/src/java/org/lwjgl/test/mapped/MappedObjectTests1.java
index bc02a406..84856e32 100644
--- a/src/java/org/lwjgl/test/mapped/MappedObjectTests1.java
+++ b/src/java/org/lwjgl/test/mapped/MappedObjectTests1.java
@@ -117,6 +117,19 @@ public class MappedObjectTests1 {
 			} catch (IndexOutOfBoundsException e) {
 				// expected, ignore
 			}
+
+			try {
+				ByteBuffer posTest = ByteBuffer.allocateDirect(200);
+				posTest.position(10 * MappedFloat.SIZEOF); // position > 0
+
+				MappedFloat vecs2 = MappedFloat.map(posTest);
+				vecs2.view = 39;
+				assert vecs2.view == 39;
+				vecs2.view = 40;
+				System.out.println("org.lwjgl.util.mapped.Checks is false or there is a bug in bounds checking.");
+			} catch (IndexOutOfBoundsException e) {
+				// expected, ignore
+			}
 		}
 
 		// test dup
diff --git a/src/java/org/lwjgl/util/mapped/MappedHelper.java b/src/java/org/lwjgl/util/mapped/MappedHelper.java
index 21977844..ca466f80 100644
--- a/src/java/org/lwjgl/util/mapped/MappedHelper.java
+++ b/src/java/org/lwjgl/util/mapped/MappedHelper.java
@@ -60,7 +60,7 @@ public class MappedHelper {
 			throw new IllegalStateException("sizeof not a multiple of alignment");
 		mo.stride = sizeof;
 
-		long addr = MappedObjectUnsafe.getBufferBaseAddress(buffer);
+		long addr = MappedObjectUnsafe.getBufferBaseAddress(buffer) + buffer.position();
 		if ( addr % align != 0 )
 			throw new IllegalStateException("buffer address not aligned on " + align + " bytes");
 
diff --git a/src/java/org/lwjgl/util/mapped/MappedObjectTransformer.java b/src/java/org/lwjgl/util/mapped/MappedObjectTransformer.java
index 6e2f5365..b3956b5a 100644
--- a/src/java/org/lwjgl/util/mapped/MappedObjectTransformer.java
+++ b/src/java/org/lwjgl/util/mapped/MappedObjectTransformer.java
@@ -62,7 +62,7 @@ public class MappedObjectTransformer {
 
 		String vmName = System.getProperty("java.vm.name");
 		if ( vmName != null && !vmName.contains("Server") ) {
-			LWJGLUtil.log("Warning: " + MappedObject.class.getSimpleName() + "s have inferiour performance on Client VMs, please consider switching to a Server VM.");
+			System.err.println("Warning: " + MappedObject.class.getSimpleName() + "s have inferiour performance on Client VMs, please consider switching to a Server VM.");
 		}
 	}