Nitpickin': Flash before/after login screen

[stevelist at silverorange.com]

File under really picky-but-every-detail-counts:

Using the default Fedora login/theme/background, right before the login screen
show, you see a blank screen with a blue background - then the login screen
comes up with the same background, but there is a quick blank/white flash before
the login screen. You get the same thing after you submit the login form.

Is this just something unique to a particular video card / driver set, or is it
something common in all installs? Any ideas why it happens and if there's
anything we can do to eliminate it?

Thanks,
Steven Garrity