HOSTS / LMHOSTS files on XP System in a AD Domain
Solution 1:
Why are you using the hosts/lmhosts files in the first place? That's just begging for problems. If your AD domain is native you should just lose those files and let DNS take care of things.
Even if it's not native, if your PC's are joined to the domain then there are very few reasons to have a big long hosts/lmhosts file with entries related to the domain they're members of common to all of them.