diff --git a/Source/Properties/AssemblyInfo.cs b/Source/Properties/AssemblyInfo.cs
index 349f4f5cd2152f71e2b2520ccc0f0e8214be5be3..f2f7b08e996756d6794cf8f09ec955337b7a9872 100644
--- a/Source/Properties/AssemblyInfo.cs
+++ b/Source/Properties/AssemblyInfo.cs
@@ -32,7 +32,7 @@ using System.Runtime.InteropServices;
 //
 // You can specify all the values or you can default the Revision and Build Numbers 
 // by using the '*' as shown below:
-[assembly: AssemblyVersion("1.5.1.*")]
+[assembly: AssemblyVersion("1.5.2.*")]
 //[assembly: AssemblyFileVersion("1.0.1.*")]
 
 [assembly: CLSCompliant(true)]
diff --git a/Source/Svg.csproj b/Source/Svg.csproj
index 36906139e0c700d4f50e994f1d2c186318cd1b3f..0869b7fa8594aed303bcf0e1407fbb5b92171f33 100644
--- a/Source/Svg.csproj
+++ b/Source/Svg.csproj
@@ -16,7 +16,7 @@
     <OldToolsVersion>3.5</OldToolsVersion>
     <UpgradeBackupLocation>
     </UpgradeBackupLocation>
-    <TargetFrameworkVersion>v4.0</TargetFrameworkVersion>
+    <TargetFrameworkVersion>v3.5</TargetFrameworkVersion>
     <IsWebBootstrapper>false</IsWebBootstrapper>
     <SccProjectName>
     </SccProjectName>
diff --git a/Source/SvgElement.cs b/Source/SvgElement.cs
index c7cf713797549291b2191cc2eeb9a3e3dd2c96d8..febac46181795355123864c55ebe7eb413901ab2 100644
--- a/Source/SvgElement.cs
+++ b/Source/SvgElement.cs
@@ -459,7 +459,7 @@ namespace Svg
 	                var evt = attr.Event.GetValue(this);
 	                
 	                //if someone has registered publish the attribute
-	                if (evt != null && !string.IsNullOrWhiteSpace(this.ID))
+	                if (evt != null && !string.IsNullOrEmpty(this.ID))
 	                {
 	                    writer.WriteAttributeString(attr.Attribute.Name, this.ID + "/" + attr.Attribute.Name);
 	                }
@@ -727,7 +727,7 @@ namespace Svg
         /// <param name="caller"></param>
         public void RegisterEvents(ISvgEventCaller caller)
         {
-            if (caller != null && !string.IsNullOrWhiteSpace(this.ID))
+            if (caller != null && !string.IsNullOrEmpty(this.ID))
             {
                 var rpcID = this.ID + "/";
 
@@ -747,7 +747,7 @@ namespace Svg
         /// <param name="caller"></param>
         public void UnregisterEvents(ISvgEventCaller caller)
         {
-        	if (caller != null && !string.IsNullOrWhiteSpace(this.ID))
+        	if (caller != null && !string.IsNullOrEmpty(this.ID))
         	{
         		var rpcID = this.ID + "/";