VB 6.0 written ActiveX in Delphi

I've created an ActiveX Control in VB 6 /Sp3 in singlethreaded or multithreaded mode. I can load this control in IDE-Mode, I can use the property-pages, I can change the properties. It is possible to change to runtime mode and use my integrated popup-menue of this control. The only problem appears if I use the programming COM interface of the Control by calling a methode or set a property.
In Delphi I get the error-message " Project ... raised exception Class EOleException with message "not valid property value" process stopped !"
In Excel I get the error-Message " Class does not support automation"

In VB5 / VB6 / IE4 /VC++ the control is working correctly.

if your using Delphi 4, try converting the ActiveX Control to a Delphi component
....they are much more stable in Delphi then Active X.