Ok, this is not me. Its my friend (username [SNEK]), who, in an attempt to prevent an epic babelfish post, asked me to explain the problem.
He had to format his harddrive and reinstall XP Pro (SP2).
Now, sometimes when he reboots, LFS asks for an unlock. And he ran out of unlocks.

What he asks is help AND an extra unlock so he can play. (hes addicted to LFS as if its caffeine).

So.. what gives? I find this puzzling cause I installed vista over XP, didnt install lfs, just created a shortcut, and away I went... in his case, should have been a cakewalk.

Keep in mind, he did NOT delete LFS - it was in another partition, is latest version, no crazy mods, etc.

EDIT: 2 new facts:
1- BEFORE formatting, lfs was already occasionally asking for a new unlock, upon restarting the PC (not always, occasionally)
2 - He bought and installed (after formatting) a new GFX card (which should mean anything, but the more facts, the better)

This has been known to be caused by a Windows PC going into hibernate - does he use that?

Also can you get him to check to make sure that the entire data directory, in particular the data/misc directory is writable with his user account and that the existing files are not read only.

With regards to the unlock, the only way he'd get that would be to contact the devs directly here:
http://www.lfs.net/?page=mailus

nope, not using hibernate.

Could it be some power-saving thingy? (no use of that, either)