I have an applicatioin written in VB.NET (Visual Studio 2008 Pro). It
currently reads and writes to Excel 2000, 2002 & 2003 via Interops.
I now need the application to support Excel 2007

When I attempt to use the application on a PC that has Excel 2007 installed,
errors occur in the application and it crashes.

I've been distributing Excel Interops with the application.

My questions a
What Interops should I be using?
Are they (the interops) backward compatible?
Should I expect to see a lot of code changes?

PS - I posted these questions on the Visual Studio Tools for Office forum
and was told to use this forum instead.