my first guess is perhaps you have extended desktop on? from your description it sounds similar to an issue i've seen on 2000sp2 when it minimizes to the right even though you think you can see your window list on the taskbar in its entirety. just a guess. in case you dunno where to check for extended desktop, right-click desktop -> properties -> settings tab? sorry i don't have xp handy atm. you might try checking there and possibly like advanced monitor settings and such.
i also recommend you don't post on a ski site for computer help. :p I've heard good things about the site below: