安装2007兼容包后，Office主互操作程序集无法正常工作

I had a C# program that did some Word & Excel automation and it used Office 2003 Primary Interop Assemblies. The way I deployed it was by including the Interops in the bin and I had my program reference it from there as opposed to referencing it from the GAC (not very professional, but it worked fpr years). Recently on 3 machines the office 2007 compatibility pack was installed and now when ever my software trys to invoke Word or excell I get an error that: I had a C# program that did some Word & Excel a