Let's not take this in the same direction as the last thread went please.
Problems dual-booting Linux and Windows XP are plentiful, well documented, usually easy to solve, and are usually split fairly evenly between being caused by Windows and caused by Linux.
9 times out of 10 it's a small mistake made in the install process that causes the problem, and it's an equally small change needed to fix it.
Once you've got the two re-installed (install XP first,
then Ubuntu) you should find things start to run more smoothly. If you're still having problems you will probably find that the guys & gals at the
Ubuntu Forums can get you sorted and up and running in no time at all - they're a friendly bunch, who don't usually get involved in OS flaming wars (from either side of the fence), and who are more interested in helping people decide if Ubuntu is right for
them rather than getting evangelistic about it.
If you do post over there look for a member called Catsworth, tell him I said "Hi"