Through a toilet roll?

It is, and if you look at the picture on the review it shows it's the mark II. Maybe they actually tested with the old model and didn't realise that there's a new one - seems like a mistake in the review.

Nice review over there for those trying to resist
http://www.trustedreviews.com/digital-cameras/review/2008/04/18/Pentax-K20D-digi...

Oops

Those are very nice indeed and I do like the strong lighting in the shots and they're well captured.

It's always difficult with the little guys and all the branches in the background to get it to blend more. I can't see the EXIF data, but it might be worth using a smaller f stop if possible to help blur it out more (reducing the DOF), though you may lose sharpness in doing that, depending on the lens.

One other small point, the pictures seem to have a touch too much PP sharpness for my personal taste.

I really like the daisy. It can be so difficult not to blow out the whites on the petals and you've done really well with it, for me.

The 100% crop looks too regular to me, suggesting electrical interference (or maybe the SD card). You didn't have your mobile phone or anything like that near the camera at the time? I haven't noticed any banding with my K20D yet and the higher DR settings side-effect that I've seen is just more noise in dark areas.

Oh, and did you turn SR off especially when it was tightened?

I'd also suggest looking for the 'A' lenses where possible to start off with, it gives you more flexibility and time to learn about the different aspects of SLR photography. Getting a cheap M lens to play with would be a bit of fun if you want to learn more about manual only.

This recently posted article may (or may not) shed some light on the issues of sensor technology:
http://www.anandtech.com/digitalcameras/showdoc.aspx?i=3290

There's to be a follow-up article that tackles the issue of noise in more depth.

A much more expensive solution:
http://www.speedgraphic.co.uk/prod.asp?i=8510&1=Novoflex+UNIMARM+Macro+Brack...