diff --git a/lib/x11/corereqs.js b/lib/x11/corereqs.js
index 1dddafa..9e67cc9 100644
--- a/lib/x11/corereqs.js
+++ b/lib/x11/corereqs.js
@@ -187,6 +187,20 @@ module.exports = {
        }   
    ],
 
+   ChangeProperty: [
+       // mode: 0 replace, 1 prepend, 2 append
+       // format: 8/16/32
+       function(mode, wid, name, type, units, data)
+       {
+          var padded4 = (data.length + 3) >> 2;
+          var pad = new Buffer( (padded4<<2) - data.length);
+          var format = 'CCSLLLCxxxLaa';
+          var requestLength = 6 + padded4;
+          var dataLenInFormatUnits = data.length / (units >> 3);
+          return [format, [18, mode, requestLength, wid, name, type, units, dataLenInFormatUnits, data, pad] ];
+       }
+   ],
+
    QueryPointer: [
        [ 'CxSL', [38, 2] ],
        function(buf) {
diff --git a/lib/x11/unpackstream.js b/lib/x11/unpackstream.js
index 1e963b6..d20d975 100644
--- a/lib/x11/unpackstream.js
+++ b/lib/x11/unpackstream.js
@@ -219,7 +219,8 @@ UnpackStream.prototype.pack = function(format, arguments)
         } else if (f == 'p') {
             packetlength += xutil.padded_length(arguments[arg++].length);
         } else if (f == 'a') {
-            packetlength += arguments[arg++].length;
+            packetlength += arguments[arg].length;
+            arg++;
         } else {
             // this is a fixed-length format, get length from argument_length table
             packetlength += argument_length[f];
@@ -228,9 +229,6 @@ UnpackStream.prototype.pack = function(format, arguments)
     }
 
     var buf = new Buffer(packetlength);
-    for (var i=0; i < packetlength; ++i)
-        buf[i] = 255; 
-  
     var offset = 0;
     var arg = 0;
     for (var i = 0; i < format.length; ++i)
diff --git a/lib/x11/xcore.js b/lib/x11/xcore.js
index e62ddc3..ec821f4 100644
--- a/lib/x11/xcore.js
+++ b/lib/x11/xcore.js
@@ -15,7 +15,7 @@ require('./unpackbuffer').addUnpack(Buffer);
 
 var xerrors = require('./xerrors');
 var coreRequests = require('./corereqs');
-var stdatoms = require('./corereqs');
+var stdatoms = require('./stdatoms');
 
 function XClient(stream)
 {
@@ -119,10 +119,11 @@ XClient.prototype.importRequestsFromTemplates = function(target, reqs)
 
                  if (callback)
                      this.replies[this.seq_num] = [reqName, callback];
-                                                                            
-                 //console.log([format, requestArguments]);
+                 
                  client.pack_stream.pack(format, requestArguments);
+                 var b = client.pack_stream.write_queue[0];
                  client.pack_stream.flush();
+                 
             } else if (templateType == 'Array'){
                  var format = reqTemplate[0];
                  var requestArguments = [];
diff --git a/lib/x11/xutil.js b/lib/x11/xutil.js
index 87e4599..d75b2b6 100644
--- a/lib/x11/xutil.js
+++ b/lib/x11/xutil.js
@@ -1,10 +1,13 @@
 function padded_length(len)
 {
+   return ((len + 3) >> 2) << 2;
+   /*
    var rem = len % 4;
-   var padded_length = len;
+   var pl = len;
    if (rem)
-       padded_length = len + 4 - rem;
-   return padded_length;
+       return len + 4 - rem;
+   return len;
+   */
 }
 
 // TODO: make it return buffer?
diff --git a/test/changeprop.js b/test/changeprop.js
new file mode 100644
index 0000000..d2181f5
--- /dev/null
+++ b/test/changeprop.js
@@ -0,0 +1,23 @@
+var x11 = require('../lib/x11');
+
+var xclient = x11.createClient();
+var PointerMotion = x11.eventMask.PointerMotion;
+
+xclient.on('connect', function(display) {
+    var X = this;
+    var root = display.screen[0].root;
+    var wid = X.AllocID();
+    var white = display.screen[0].white_pixel;
+    var black = display.screen[0].black_pixel;
+
+    X.CreateWindow(wid, root, 10, 10, 400, 300, 1, 1, 0, { backgroundPixel: white, eventMask: PointerMotion });
+    X.MapWindow(wid);
+
+    // mode: 0 replace, 1 prepend, 2 append
+    // mode, wid, name, type, format, data
+    X.ChangeProperty(0, wid, xclient.atoms.WM_NAME, xclient.atoms.STRING, 8, 'Hello, NodeJS');
+ 
+    setInterval(function() {
+           X.ChangeProperty(0, wid, xclient.atoms.WM_NAME, xclient.atoms.STRING, 8, 'Hello, NodeJS ' + new Date());
+    }, 100);
+});
\ No newline at end of file
diff --git a/test/genstdatoms.js b/test/genstdatoms.js
new file mode 100644
index 0000000..795a96e
--- /dev/null
+++ b/test/genstdatoms.js
@@ -0,0 +1,28 @@
+var x11 = require('../lib/x11');
+
+var xclient = x11.createClient();
+var atomId = 1;
+xclient.on('connect', function(display) {
+    var X = this;
+    function listAtoms()
+    {
+        function getAtom(a)
+        {
+            X.GetAtomName(a, function(str) {
+                if (a == 1)
+                    console.log('module.exports = {')
+                if (a != 68)
+                    console.log('    %s: %d,', str, a);
+                else
+                    console.log('    %s: %d\n}', str, a);
+                listAtoms();
+            });
+        }
+        if (atomId <= 68)
+           getAtom(atomId);
+        else
+           X.terminate();
+        atomId++;
+    }
+    listAtoms();    
+});