One of these VMs is not like the other

The theme this month is "your Dev box will do weird things, for no explicable reason"... As I mentioned earlier, I've switched from using XP Pro as my Host OS, to using Ubuntu 7.10 (64 bit edition). As a side-effect of other Dev upgrades, I now have 2 guest OS images running XP Pro: my "old dev environment", and the "new" one.