Thanks for the reply.
I was using Ilford paper but that got expensive for tests so I switched to paper we can get in the Uk that is 'manufactured by Ilford' and for which the Ilford profiles work and they have for me in the past.
I have moved on a little as I realised roughly what you said, it had to be something to do with the Canon printing software so I restored all defaults, then chose the appropriate paper type and another setting but left the ICC profile at auto and I then got the best print yet. So, I guess I may have a solution for this ink but I will want to try it with a genuine Canon cartridge to make sure it's not something that's happened within the Canon printing software.
My suspicion is that the Canon printing software knew the PM cartridge was empty, and therefore didn't use it. When I put the compatible in sure it wasn't empty but neither was it genuine and I wonder if the software was refusing to use it? The printer driver knows it's a full cartridge and reports it as such but wonder if the printing software is craftier. Canon do like you to buy their ink.
I'm going to have a poke about in the registry - just for kicks.
Once again thank you for replying and offering help.
Mike