Sorry if I don't do this right. It's my first bug report. I cannot upgrade now to 4.8.0, so I don't know if it's already fixed. But I've not find anything about that. I will try to update the bug report when I upgrade QT.

1. Create a QT GUI. You can use qtconfig itself and avoid to create any new GUI.
2. Run "qtconfig &" and set "Select GUI Style:" to "Desktop Settings (Default)".
3. Run "sudo qtconfig &".
4. The first window has Ubuntu theme (GTK+), but the second one has a different theme. Exactly the same as if you run "gksu qtconfig &".
5. It's the same when you run the app in other machine with Ubuntu using ssh+x11 (with or without sudo).
6. Change "Select GUI Style:" to any other theme.
7. Now both themes (sudo theme and "no-sudo" theme) are the same.
8. gksu keeps its own theme (this is logic).

Regards.