There's not a lot to go on but there may be a clue in that truncated file. This implies that part of the system may have become corrupt. Have you tried using one of your restore points? I'm fairly new to XP so can't be sure how well these work, but from the tales I have heard, if you can go back far enough to before the problem first occurred, you can clear most problems. If that doesn't work, try a repair from your install CD.