"Aero Snap" =/= "Aero", I think.
I'm actually on balance with PeeWee on this. Yes, it's annoying sometimes, but helpful slightly more often. Two things, though:
1) I've got "Aero" off too, I think (that *is* the silly transparent-windows Fisher-Price II interface from Vista, innit?), and the snappy-thingy behaviour still present in my "Windows Classic" theme. But following the instructions on the page Peter linked, I was able to turn it off. I'm guessing the snappy-thingy, "Aero Snap", can be turned off even if one has the ugly stupid "Aero" visible theme enabled (not that I'm even going to try enabling the latter). TL;DR: Aero Snap is not Aero; it needs to be separately disabled as per the linked page.
2) Another quick tip that might help: Contrary to Peter's perhaps overly-terse summary, I found that (at least on my StinkPad) Win-down first restores a maximized window to its previous size, and only then minimizes it on the next press. Likewise, Win-Left or Win-Right don't just snap the window to the respective edge, but on successive keypresses they cycle through the range of Windowed-center, snap-to-edge, other-edge, center... Left- or rightwards depending on which arrow key you use. (This thing is actually looking better and better -- Thanks, PeeWee!) The Win-Up/Down key combo doesn't cycle that way, though; there, you have to alternate Up- and Down-arrow.
Christian R. Conrad
Same old username (as above), but now on iki.fi
(Yeah, yeah, it redirects to the same old GMail... But just in case I ever want to change.)