VB app terminating immediately

I'm experiencing a strange problem: a VB client app is terminating
before even executing the first line of my Sub Main.

It works fine on my development machine but on all test machines all I
get is a double bleep from the PC speaker when I launch the main EXE and
then the app just dies. I put a msgbox in the first line of Sub Main as
a trap but that doesn't even appear.
My guess is it is something to do with a bad DLL/OCX registration but
I've never seen that effect before.
It did run on a test machine a couple of times. Then I did a recompile &
a rebuild of the InstallShield package to fix a couple of tiny bugs. Now
I cannot seem to go back to that state.


Regards,

Alex Bailey
Interfacia Ltd.