Why couldn't access properties of ActiveX control

I use C++ Builder4 to write a custom VCL component. And now I need
the component to ActiveX control in order to be used in powerbuilder.
And I use
ActiveX Wizard to generate from VCL component, but I couldn't access any
of this ActiveX control. Acturally, I could browser those properties by
of powerbuilder, but can't access.
Also I tried a very simple component. First, I generate a ButtonX
ActiveX control
from VCL component--TButton, then I could acess property 'Caption' of
ButtonX in
powerbuilder. Then, I generate a custom component TButtonTmp from
TButton with
new component wizard, and generate a ButtonTmpX ActiveX control from
finally I couldn't access property 'Caption' of ButtonTmpX in
Why does it occur?
Please help, thank you very much!

Qingsong Xu