I am the friend tarey is referring to. I have a similar computer, with 2.4 P4C instead of the 3000+, and a Samsung 17". I bought the UPS, and found this problem on the first day.
If I just turn off the monitor and turn it on a short time later, then there isn't any problem. However, leaving the monitor off 4-5 minutes, and then turning it on causes everything attached to the UPS to restart.
I talked to my dealer and he said that this is a known problem, and he will talk to the Microtek service guy when possible (3-4 days ago, no reply yet). I hope this means that the problem is solvable.
I just bought a Samsung 740N 17" LCD, and of course there is no problem with that. LCDs consume far less power, and the CRT powering up put a load on the UPS. Our UPS' are unable to handle the load and trip.
Another problem with the UPS, as I discovered, is that if there is a power failure, the system and the monitor stays on properly, but my modem (standard BSNL DataOne Huawei modem) resets. I don't think anything can be done about this problem, but I hope that the above problem is fixable. Vyasram, how do you connect to the net? Do you have any such problem.
Vyasram, take the UPS to your Microtek service center, and let me know if the problem gets fixed. If I find out anything more first, I will post it here.