Based on the ThararezLook I've created my own GUI sheet which works perfectly.
I've run into a bump though. I've got a MouseCursorImage on my editable boxes, that looks like the windows one.
It has those horizontal lines which gives it a larger width. So when I click in my editbox, the text carat moves to where the left corner of my mousecursorimage is rather than the middle of the mousecursorimage, which is the windows-style.
I tried messing with properties, but without success.
What to do, what to do?

Image that shows the mousecursor style: http://img171.imageshack.us/i/ceguiissue.jpg/