Insatallation Problem

I have developed an app using VB6 ent SP5. The application references the default references +ADO2.6 I use 2 comm controls some buttons, labels and text boxes. 1 class module and 1 bas module. when I compile and run the app on the dev box (win98) it all runs fine. If I use the package & deployment wizard it creates the setup no probs. When I install the app on another machine (Win ME) it installs with no errors. MDAC is also loaded. When I run the app on WinMe it loads fine, but then without fail I get an error 5 invalid procedure call or argument. I never get this message on the dev machine.

Well can you stick in MsgBoxes all over the place to track it down to which line is causing the error ?