Different .NET assembly references depending on 32-64 bit [duplicate]

Question

I've got a 32 bit and a 64 bit .NET assembly from a supplier. They have the exact same interfaces in them (same classes, same methods, etc.)

For some reason, I can never run one type on the other platform. What I've been doing thus far is simply to remove the references and then recompile as appropriate.

Is there a simpler way to do this?

EDIT

I was thinking SVN could be co-opted to solve this somehow?

EDIT

The assemblies are not in GAC. And also, the need arises because I'm building the same program on both platforms, rather than trying to run something built on one platform on the other.

Answer 1

maybe this helps: Conditional Reference in VS 2010

EDIT: here is a better description: Conditionally use 32/64 bit reference when building in Visual Studio