Are you running Vista? Do you have dual monitors? Last question: do you have them stacked vertically?
The startup monitor position in Vista looks like this:

After every startup I alter the monitor position as follows:

Why do I have to do this? Why is this personalization not persisted? I really don't know. I presumed the much-touted multi-monitor support included in Vista SP1 would provide a solution, but alas, no.
I am curious to know others' experience. Keep in mind that I logon using a Limited User Access (LUA) account - although the behavior does not change when I startup as a member of local Administrators group.
Comments
Wow, is that two 27" widescreen displays stacked on top of one another? What do you DO on that thing?
I've got 2 monitors - but they're side by side, so the config settings stay put. A 24" widescreen and then, to it's right, a 20" widescreen flipped on it's side in a portrait configuration. Which, I thought was a pretty spiffy config, but now... two 27" stacked on top of one another.
I'm going to have to rethink this.
All you dev heads out there should go read Abby's blog. She gets it.
Yeah, Abby, I guess I prefer the vertical stack - and I've tested that preference for two months now by using side-by-side arrangement. (I was forced into this after a move to a temporary house where I don't want to drill mounting hardware into the wall.)
I highly recommend 27" over 24" to anyone making a new purchase. Text is considerably larger and thus much less work on the eyes. When I work from Steve's house (24" monitors) I feel the difference.
What does one do with so much real estate? Well my typical setup is the following:
Now what I really want is one of those spiffy tablets like you have. Steve and I are currently in the research phase for a new product, code named "The Kitchen", that is geared towards touchscreens. :^)