Awstats showing 404s for pages and objects I definitely don't have...

Question

I have a HostGator site using Awstats and I've recently noticed the following 3 bizarre 404s:

[address]                      [times]
/images/wikimedia-button.png     1
/apple-touch-icon.png            1
/imgs/custom-space.gif           1

the first and third also carry referrers from within my site, but are 100% definitely absolutely not linked by any of my pages.

I'm not too worried about it, seeing as each one has only popped up once. But I am concerned about why Awstats thinks one of my pages is referring what is apparently a wikipedia image, and why Steve Jobs is trying to haxx0r me (/joke)

This is my first site to receive moderate daily usage, so I'm curious if these sorts of unique weird-o 404s just come with the territory, or if I should be double-checking something...

Thanks!