Yeah that's a bit of a problem with VB.NET: in C# you just specify you implement an interface and the compiler figures it out. In VB.NET, they thought it would be nice to do some extra nagging by adding the requirement to specify which interface method you actually implement (which is totally irrelevant for the CLR)
So when you port the code, you should take the actual interface definitions and add the proper specifications (Implements IFoo.Bar) , and that's about it I think