在运行.NET自定义操作之前强制安装GAC？

I'm using a VS 2008 Setup and Deployment project to deploy a mixed managed / unmanaged application. I've had trouble registering mixed-mode DLL's using the built-in registration property ("vsdraCOM" enumerated value of the "Register" property.) As a workaround, I've added a .NET custom install assembly (with a class that derives from System.Configuration.Install.Installer.) I'm certain that that class is running and a number of operations successfully install and uninstall through code in that assembly, including executing the Dll(Un)RegisterServer entry point of a number of assemblies. I'm using a VS 2008 Setup and Deployment projec