“Object Reference Not Set to an instance of an object” when creating Sequential workflow

I am working with SharePoint 2007 custom workflows. When I add a sequential workflow (New Project -> Workflow -> SharePoint 2007 Sequential Workflow) it gives an error as "Object Reference Not Set to an instance of an object" error. After searching I found out that 64 bit machines causes this error. I tried several times and Is there a workaround to create custom sequential workflows in Share-point 2007 in 64 bit machine? Following are my s/w specifications of my machine.

I have SharePoint 2007 installed in Windows Server 2008 R2 Standard, and Visual Studio Team System 2008 is used for developments.

Thanks in advance!