This has happened a couple of times since installing SP2, at least I think it started here.  On bootup, the Desktop would revert to 1024 by 768 pixels at High (24 bit) color quality, and most icons were lined up at the upper left.  The settings I prefer are 800 by 600 at Medium (16 bit), with icons at center screen.

I don't recall this ever coming up with SP1.  But I think I know what's happening.  Sometimes I'll switch off the monitor and go do something else, come back later and decide to switch the whole computer off, without powering up the monitor again first.  The next time I flip the machine on, I might forget to turn the monitor back on until later in the boot process… like say, when I see there's nothing on screen and no green light by the power switch… haha. :)

So I'm thinking that it has something to do with my PnP monitor (Samtron 76V) and driver, the way they work with SP2, or the way it works with them.  If the system can't 'see' the monitor (said monitor having been turned off), then maybe in its bafflement, XP uses the defaults.  If the monitor stays on and I do a restart, the problem goes away-- the Desktop appears with the settings I prefer.  Btw, it has to be a restart-- logging off and back on won't fix the problem.

Why this should happen with SP2, that part is still a mystery.  I have the latest drivers for this particular monitor… got them at Windows Update…   Maybe they're the same drivers MS had before SP2, only they exhibit this strangeness with the new service pack.  I could compare driver revision numbers but I'd rather not, doesn't seem worth it somehow.

However, I did a test of sorts.  I turned off the monitor and restarted XP.  Low and behold, the same thing happened.  I'm not bothered by it, not now.  If such behavior is consistent and its cause can be traced, I can live with it more easily, even if I can't change it.