I actually emailed Canon outlining my problem above and recieved a phone call and the following email explaining...
"Further to our conversation just now, I am writing regarding your recent call to our helpdesk regarding opening RAW files in DPP with your G10 (and EOS 350D).
The sharpness settings in the actual RAW files on both the G10 and 350D are the same, it is the DPP software that is actually trying to apply the extra sharpness. You will be able to see this if you open the EXIF data in DPP (‘File’ > ‘Info’) and another application such as ZoomBrowserEX for example (right click on image > ‘Properties’), the sharpness setting is ‘Normal’.
As you are aware, when you open the image in DPP, the sharpness will be set at 6. This is actually as a result of the Picture Style which DPP is applying to the image. Just to demonstrate this, go to ‘Picture Style’ just above the histogram on the tool palette, and use the drop down menu to change from ‘Standard’ to ‘Monochrome’. You will see that this will change the sharpness to 3, as well as changing a couple of other settings.
So basically, we want you to be able to open all images at zero sharpness. To do this, select your chosen picture style if you desire (Standard is default), and move the sharpness slider to zero. Next, go to ‘Edit’ on the top toolbar, and click on ‘Save Recipe In File’. This is basically going to save your chosen settings to a template. Save the file to an easily accessible folder as you will need to refer to this every time you import new images.
The main part is now done, but just to illustrate how to apply this template to future images, select a folder of images that you want to apply the zero sharpness setting to.
Select the images or click the ‘Select All’ icon just below your main toolbar along the top.
Then right click on the selected images and go down to ‘Read and Paste recipe from file’.
The ‘Open’ dialog box will appear, please locate the template file that you saved just now.
Once selected, please click Yes to the ‘Apply Recipe to All Selected Images?’.
You will notice that the screen refreshes as a little asterix appears just to the right of the file names to indicate that changes have been made to the files. This has now applied zero sharpness to all of the selected images as well as any other changes you may have made to the template.
To demonstrate this, please open the tool palette to see the sharpness slider is set to zero.
As advised above, this is only necessary because of the Picture Style settings that DPP is trying to apply. If you were to open the file in another application that does not support picture styles, these steps would not be necessary as no sharpening will be applied".
A very helpful and detailed reply - but, is it really any easier than to 'select all', slide the sharpness slider to zero, close DPP, and then click 'yes to all' when prompted to accept the changes? Then, re-open DPP with all files set to zero sharpness. Although this would have to be repeated whenever new files are added which was my initial concern.