Barney,
Although the power steering does make quite aloud whining noise, some of the 2003
MCS's did have steering rack problems, including mine. The main thing to keep an eye on is the fluid level, which is the black plastic reservoir at the back centre of the bonnet just under the windscreen. You should be able to clearly see the fluid.
On mine it had lost most of it's fluid and was getting increasingly more noisy as time went by. In the end they replaced the whole rack and (touch wood) it hasn't been a problem since.
Hopefully it's just you not being used to the noise it makes, so I'm not trying to worry you, just making you aware of an old problem.