Gui editor Mouse control

Hi.

I am trying to mod the starter.racing Gui. Unfortunatly the mouse cursor is going haywire.
1. When trying to resize the properties pane it fills the screen,
2. When trying to move elements around with the mouse it gose in the wrong direction completely,
3. When moving elements they disappere, then become deselectable
4. when re sizing elements i get all of the above.

Any help would be really greatful at the moment, i cant work it out for sh!t