Can someone advice me.

I have taken a couple of photos of sunsets and sunrises (please look at my posts - username "nathanrippon") and was showing a friend my pics, and he adviced fairly strongly that i didnt take photos of this theme as the sunrays will damage the cameras sensor.

Can someone confirm this theory, or advice what safteguards i can take to avoid damage to my camera?

The manual for my KonicaMinolta DimageZ3 says that when taking pics of sunrise/sunset don't keep the camera pointed at the sun or if you do, cover it in between shots.

So, I think so long as you don't keep it aimed at the sun permanently, you should be OK.
I have taken many sunset pics with my camera, and have seen no ill effects.

The intensity of the sun at sunrise and sunset is not sufficient to damage a sensor in the length of time you'd be pointing the camera at the scene. In any event, on a DSLR, the sensor is only exposed to the sun at the moment of image capture.

So, in the main, this is a myth.

Of course it would be pretty stupid to point the camera at full daytime sun with a long lens attached