This is probably because you are running different versions of microsoft excel on the two platforms. When Microsoft changes the activex controls, then this will make the VI un-executable. If you mass compile your application, then you should find one of the VIs to be broken, and you can go fix/refresh that activex control.
If you want it to be executable on multiple versions of excel, you'll need to create the logic to switch between the two different controls (and maybe use VI server to load certain versions of VIs)
