What's the use of interfaces with structures?

Hey,
I was just playing with a structure (to solve my last binary IO problem) and I came up with a strange thing...

You can write a structure that implements an interface. I can then create an interface variable that I then set to the structure variable. In this way, I can access the interface methods (blah...blah...blah).

Anyway, what I noticed is every time I change a property in the structure I lose synchronization. I have to set the interface variable to the structure variable again. I'm assuming this is because dot net didn't create a reference but a copy for me...

This is OK, when I change the value of the struct, but when I change the struct through the interface, it doesn't take:

StructVar.TestVal = 50;
ITest = StructVar;
ITest.GetVal; <returns 50> // ok

but...

ITest.SetVal(25);
StructVar.TestVal; <returns 50> // not OK

any ideas how to make this work?

Structs are value types, you might want to try boxing.