My system clock on my XP system will not stay advanced 1 hour for Daylight Savings Time. After about 1 hour it will jump back to one hour earlier. It should have changed automatically for DST since I had the box checked, but it didn't, so I thought it odd I had to change it manually for DST. But it won't stay changed, it keeps jumping back an hour after about an hour's time. Any ideas? Thanks in advance