diff --git a/Netdisco/share/public/javascripts/netdisco-util.js b/Netdisco/share/public/javascripts/netdisco-util.js
index 85599279..3159ac61 100644
--- a/Netdisco/share/public/javascripts/netdisco-util.js
+++ b/Netdisco/share/public/javascripts/netdisco-util.js
@@ -24,7 +24,7 @@ function formatMacAddress(macaddr, format) {
   var fmac = '';
 
   if (!mac.test(macaddr) || !fmt.test(format)) {
-    return '';
+    return macaddr;
   } else {
     macaddr = macaddr.replace(/[:-]/g, "").toLowerCase();
     format = format.toLowerCase();
@@ -41,8 +41,13 @@ function formatMacAddress(macaddr, format) {
         fmac = convertMacAddress(macaddr, "-", 2).toUpperCase();
         break;
 
-      default:
+      case 'sun':
         fmac = convertMacAddress(macaddr, ":", 2);
+        fmac = fmac.replace(/0([0-9A-F])/gi, '$1');
+        break;
+
+      default:
+        fmac = macaddr;
         break;
     }
   }
diff --git a/Netdisco/t/netdisco-util.html b/Netdisco/t/netdisco-util.html
index 33ff973a..8fe13d59 100644
--- a/Netdisco/t/netdisco-util.html
+++ b/Netdisco/t/netdisco-util.html
@@ -47,21 +47,21 @@
     });
 
     QUnit.module("formatMacAddress");
-    QUnit.test("sun to ieee", function(assert) {
-		var mac = "01:23:45:ab:cd:ef";
-		assert.deepEqual(formatMacAddress(mac,'IEEE'), "01:23:45:AB:CD:EF");
+    QUnit.test("pg to ieee", function(assert) {
+		var mac = "01:23:45:0b:cd:ef";
+		assert.deepEqual(formatMacAddress(mac,'IEEE'), "01:23:45:0B:CD:EF");
     });
-    QUnit.test("sun to cisco", function(assert) {
-		var mac = "01:23:45:ab:cd:ef";
-		assert.deepEqual(formatMacAddress(mac,'Cisco'), "0123.45ab.cdef");
+    QUnit.test("pg to cisco", function(assert) {
+		var mac = "01:23:45:0b:cd:ef";
+		assert.deepEqual(formatMacAddress(mac,'Cisco'), "0123.450b.cdef");
     });
-    QUnit.test("sun to microsoft", function(assert) {
-		var mac = "01:23:45:ab:cd:ef";
-		assert.deepEqual(formatMacAddress(mac,'Microsoft'), "01-23-45-AB-CD-EF");
+    QUnit.test("pg to microsoft", function(assert) {
+		var mac = "01:23:45:0b:cd:ef";
+		assert.deepEqual(formatMacAddress(mac,'Microsoft'), "01-23-45-0B-CD-EF");
     });
-    QUnit.test("sun to sun", function(assert) {
-		var mac = "01:23:45:ab:cd:ef";
-		assert.deepEqual(formatMacAddress(mac,'Sun'), "01:23:45:ab:cd:ef");
+    QUnit.test("pg to sun", function(assert) {
+		var mac = "01:23:45:0b:cd:ef";
+		assert.deepEqual(formatMacAddress(mac,'Sun'), "1:23:45:b:cd:ef");
     });
     QUnit.test("microsoft to ieee", function(assert) {
 		var mac = "01-23-45-AB-CD-EF";
@@ -76,8 +76,8 @@
 		assert.deepEqual(formatMacAddress(mac,'Microsoft'), "01-23-45-AB-CD-EF");
     });
     QUnit.test("microsoft to sun", function(assert) {
-		var mac = "01-23-45-AB-CD-EF";
-		assert.deepEqual(formatMacAddress(mac,'Sun'), "01:23:45:ab:cd:ef");
+		var mac = "01-23-45-0B-CD-EF";
+		assert.deepEqual(formatMacAddress(mac,'Sun'), "1:23:45:b:cd:ef");
     });
     QUnit.test("ieee to ieee", function(assert) {
 		var mac = "01:23:45:AB:CD:EF";
@@ -92,8 +92,16 @@
 		assert.deepEqual(formatMacAddress(mac,'Microsoft'), "01-23-45-AB-CD-EF");
     });
     QUnit.test("ieee to sun", function(assert) {
-		var mac = "01:23:45:AB:CD:EF";
-		assert.deepEqual(formatMacAddress(mac,'Sun'), "01:23:45:ab:cd:ef");
+		var mac = "01:23:45:0B:CD:EF";
+		assert.deepEqual(formatMacAddress(mac,'Sun'), "1:23:45:b:cd:ef");
+    });
+    QUnit.test("unknown format", function(assert) {
+		var mac = "01:23:45:0b:cd:ef";
+		assert.deepEqual(formatMacAddress(mac,'unknown'), "01:23:45:0b:cd:ef");
+    });
+    QUnit.test("illegal mac", function(assert) {
+		var mac = "01:23:45:0d:ef:gh";
+		assert.deepEqual(formatMacAddress(mac,'unknown'), "01:23:45:0d:ef:gh");
     });
 	</script>
 </body>