Descriptive Problem Summary:
Interface controls when drawn on top of the map can become dirty in certain situations.
Numbered Steps to Reproduce Problem:
Try this: http://www.joeysturgis.com/dirtyinterface.zip
After running in Dream seeker, try clicking in many different spots on the green squares located in the map. After a few clicks, the button will appear "dirty" with remnants of random graphical content.

Expected Results:
I would expect that interface controls are drawn properly with no "dirty graphics" remaining on top of them.
Actual Results:
The previous location under the control is drawn on top of the control at times.
Does the problem occur:
Every time? Or how often?
Always!

Workarounds:
I haven't found any workarounds but from making this I realized there really is no easy way to get the actual mouse x and mouse y location on the map control which is pretty inconvenient. I suspect this is to reduce lag (data transformation of non-used information) and could expose security (client keeping track of x y data, and hacks allowing the abuse of that), but honestly can't we have a little more client knowledge?

Anyways, there's a bug here.

This apparently only occurs when I'm "using graphics hardware". I cannot make the button become dirty in software rendering mode.