I experienced the exact same problem as mentioned in this post. Replaced the cmos battery myself, but after two weeks the problem returned. Even though my warranty expired two years ago, Dell replaced the cmos battery and motherboard free of charge. This is due to Norway's excellent consumer protection laws.
However, it's now been another two weeks and sadly, the problem has returned. It starts by windows clock slowing down. About 4 weeks after that the computer will crash before bios even loads with only one line: "Time-of-day clock stopped".
At this point your options become severely limited, but replacing the cmos clock will get you up and running again for a while.
I will contact Dell again today and see what they say. But it seems a new motherboard and cmos battery did not fix the problem, so save your money.
I have the same problem.
Interestingly though, my XPS1330 was purchased in early 2008, so its around 5 years old - the life of a battery...
Hopefully that is all it is, so once i can source one of these sealed/pigtailed batteries i will post here whether it resolved the problem.
I have recently installed an SSD with a clean OS install of Vista32, a few things have not been quite right since that was done, screen not always recovering from sleep, keyboard sometimes typing back a few lines.. will try to debug, as this machine has been a mix of pleasure and pain. The GPU timebomb is always in the back of my mind, but when this machine is working its great!
I was just wondering if you ever found the solution to this, as I have exactly the same problem. I have, like you did, done rebuilds on it, changed the cmos battery etc etc but nothing seems to cure the clock which has a mind of its own
Not sure that will be the silver bullet for everyone..
I did have this problem, and found that replacing the battery resolved it for a short period of time - around 3 months maximum. So I bought a couple of batteries off ebay and kept a spare with the lappie, have not need it lately though. I dont know if it is coincidental, but i upgraded my 1330 to Windows10 and added a Samsung SSD last December, and have not had the problem since.
This was a pain free upgrade, the only issue being the wifi driver, which is now fine. The new OS install included full firmware and driver updates, now everything is working very nicely, including the bios clock and the sleep feature - which was problematic in vista.