Carrying on from my last post ... I now realise that gconf-editor is not installed automatically with Ubuntu 11.10, so, I installed the latest version.
It shows that the trash icon box is indeed ticked, as is the Computer icon yet both are not showing on the desktop. I also have Ubuntu Tweak installed and checked in there if the desktop icon boxes were ticked to show the icons on the desktop, and yes they are. All indications are is that both icons should be appearing on the desktop ... but they don't. I have no idea where to go from here as it seems that something way too technical is involved and is possibly beyond my capacity to fathom out a solution. If you have any other ideas I would be pleased to hear them ... thanks.