Hi Bangia,
We have fixed this issue and prepared custom assemblies including this fix in the same version you are using (6.3.1.8).
http://websamples.syncfusion.com/samples/SyncfusionToolsWindows.zipHere are the steps to use the assemblies:
1. Unzip the attachment and copy-paste the assembly to Public assemblies folder (C:\Program Files\Microsoft Visual Studio 8\Common7\IDE\PublicAssemblies)
2. Remove the assembly (Tools.Windows from GAC (C:\Windows\Assembly) and drag and drop this new assembly to GAC.
3. Now compile your application and run it. Please check whether the assemblies are picked up from public assemblies folder.
Let me know if you have any difficulties in this.
Best Regards,
Kathir