My GUI does not display correctly in Webplayer, but it does display fine when I preview in Unity and in standalone builds. Today is the first time I have noticed this issue, although my GUI code has not changed significantly, only a few more controls added.
Standalone:
Web:
I am getting the impression that it previously “worked” and then as you added more function, it stopped working. The first thing I would suggest is to back up your work at this point. Next, start removing (by commenting out) chunks of code in your GUI areas. Start removing functions by halves (i.e. remove half the function). After removing a half, replay and see if the half that is still present now works or fails. If the half that remains now works, this is a good indication that something you just removed was your problem. Re-add the half that you just comment out and now focus exclusively on that part. Repeat on that area by commenting out half its function. Eventually you will end up with a much smaller set of function which, when included causes the rest to fail but when excluded, everything else works fine. When you have pinned the problem down to this area, then you can examine it closely. Experience tells me that when you reach here, you will usually be able to see the problem.