Hi Daniel,
As you can see from my reply in your other thread, the chaning of Hourglass.gif should be done via a new theme, not a modified Gizmox.WebGUI.Forms.
In order to see if your changes to Gizmox.WebGUI.Forms will get through to your application try changing something else, like adding a property to one of the controls or something like that. You will also need to be using VWG with sources installation (or the SDK), not the one Without sources. To see how to work with Visual WebGUI sources, see this article here.
Palli