Burning Speed & Win XP SP1

My Sony DRU 500A burns CD-R/RW at around 4 speed. Any ideas why and what I can do about it. This has happened since installing (I think) Win XP SP1.

I can burn DVD-R/+R at max speed. Its just CD-R/RW

what writable speeds does your dvd-rw support?

Write speeds of the drive are quoted as been
4xDVD+R, 2.4xDVD+RW, 4xDVD-R, 2xDVD-RW, 24xCD-R, 10xCD-RW

It is taking about 20 minutes to write a CD-R when it should be less than half that.

The sony drive is extremely picky with its media. Try other media as well and make sure you have the latest firmware available.

I have tried different kinds of branded media with the latest firmware.

Thanks anyway