Help: Active Problem

Good day everybody...

I have a problem with my ActiveX exe.

I created an ActiveX Exe written in VB. It'll be integrated into my Standard Exe program written in VC++.
When I first integrated it into my Standard Exe and compile it, it runs ok. I install the whole application, including the Standard Exe and ActiveX Exe, into another machine.
Now, I make some changes to the ActiveX Exe. From what I know, I do not need to compile the whole Standard Exe with the new ActiveX Exe again in order for the new ActiveX Exe to work. All I need to do is unregistered the old one and re-registered the new one and it'll work fine, right?

But, the problem is after I register the new ActiveX Exe, it refuse to run. In other words, there's no error shown when I call the ActiveX Exe. Just seems like there's nothing happen. It behaves like I've haven't register the ActiveX Exe. But I did. So what could be the problem?

Please help... It's quite an urgent matter...
Thanks in advanced.

Did you alter the interface definition? Did you change the GUID of te ActiveX object? Those two seem the most probable to me.