Hey man, One thing about your issue is bouncing around my head - that you built your theme in W7, and you get trouble when moving to your XP machine. I don't know if there is any substance to this (i only recently upgraded from XP to W7 myself) but maybe there are some permissions being set on your W7 machine that are causing problems on your XP machine? The reason i'm thinking that is because i had some trouble awhile back, when helping Adultery test his HiScore plugin. For some reason, my XP PC absolutely refused to alter a key file that he created on his W7 machine. This lead me to believe that there were permissions on this file that XP didn't understand (after all, they have gotten more complex between OS's). Adultery ultimately changed his plugin to solve the issue but i wonder if something similar is happening here with your images?