Change the GuiSliderCtrl image

I want to change the image of the slider.

So I change it at the profile, and make it display properly.
I discover that when mouse is pressed and held on the thumb. It will be shifted to wrong position
as my new thumb image was bigger than the orignal one.

So, I have made the following change in the source, TorqueGameBuilderPro\engine\source\gui\controls\guiSliderCtrl.cc

GuiSliderCtrl::GuiSliderCtrl(void)
{
	mActive = true;
   mRange.set( 0.0f, 1.0f );
   mTicks = 10;
   mValue = 0.5f;
   mThumbSize.set(32,49);
   mShiftPoint = 17;
   mShiftExtent = 32;
   mDisplayValue = false;
   mMouseOver = false;
   mDepressed = false;
}

Then, it can shift to the right place when I press the mouse on the thumb.

However, when I made the whole Gui moving.
It display some ugly thing again.
www.garagegames.com/mg/forums/result.thread.php?qt=48158