Firmware is up to date (drivers can be firmware-dependent).
The PERC 5/i comes in two variations: Adapter and Integrated. While they are very nearly identical, they have slightly different firmware. The 2950 uses the Integrated, while the Precision uses the Adapter. The driver I gave you is for the PERC 5/i on a T7500, so I would try the following (it is for 2003, not XP, so it may or may not work, but drivers for XP and 2003, because they are based on the same kernel, are usually (but not always) interchangeable):
Server 2003: