This is because Microsoft did not have Macs in mind when they made the SP2 so the upgrade software is not compatible with the Macs hardware and the 'emulated bios'.
The Boot Camp drivers need SP2 too.
If you are looking for a solution look up slipstreaming the install disc.
Drivers and drivers and driver and drivers and drivers and blah, I hate systems so dependant on drivers. Until they fixed the Boot Camp drivers, Windows on my Mac was almost unusable.
How did I know that someone would misinterpret LBA...I need sleep. You wrote 48 Bit LBA - and I almost sent you a PM asking what Laser Beam Analyzer Software has to do with XP CDs...
I use 16, 32 and 48 Bit LBA software @ work. (Thermopile, CCD and Hybrid)
So on that note - good night.