full!screen "hides" the status bar by killing the process that is responsible for displaying it. This process has other UI-related roles as well - such as forcing the refresh. The Onyx devices have a graceful way to hide and show the status bar without the side effects, but it requires some programming skills/Tasker. In one of the threads here I provided a link to a small app I wrote (
http://www15.zippyshare.com/v/17452187/file.html) that shows and hides the status bar.
Those of you who need this functionality - can you tell a bit more about the use cases? I can try to adjust this app/provide an alternative solution for you.