set_sensitive on Button not working correctly

[Sébastien Escudier <sebastien-devel celeos eu>]

Hello,

I try to use a software called GCStar.
But there is a bug on a button which stays always disabled, so I try to find 
where the problem comes from, and it might come from gtk2 library.
This problem appears on one of my computer (kubuntu 13.04) but not on another 
one (xubuntu 12.04), with the same version of the software.

So here is what I found :
There is a Button which is first disabled by calling set_sensitive(0).
Later the button should be enabled, I checked set_sensitive(1) is really 
called on that button, but the button remains disabled.
If I comment out the first call to set_sensitive(0), then the button is active.

Any help appreciated.

Best regards,
Sébastien.