sp2 - APC UPS -usb not detected

Archived from groups: microsoft.public.windowsxp.device_driver.dev (More info?)

dear friends,
I have having a strange problem after updating my windows
xp home edition with service pack 2 (sp2). from time to
time I find that the computer fails to detect a device
connected to a usb port, at other times it detects it all
ok. I am having this problem after sp2. I have an APC UPS
RS 800. this is connected to the computer with a usb
cable. sometimes when I start the computer I get the
message that the computer is unbale to communicate with
the UPS (and at other times it is all ok). when this
happens - the device manager lists "unknown device" and
says that the drivers are not installed.
please help. I would appreciate if you would kindly send
me an email at my email id.
dr manish agarwala
calcutta, india.
system info - windows xp home ed sp2, intel pentium 4 HT,
865 gbf motherboard intel, apc ups rs 800, 512mb
transcend ram, 80 gb samsung hard disk, msi dvd rom
drive.