This isn't bots (that have to execute javascript to be showing up anyhow) and more likely a tracking problem for your SEO/PPC. We quite commonly see direct traffic rise when campaign info isn't available.
Other than that, I've seen this occur when two conflicting tracking scripts were being called on the page.
I just checked www.mac-forums.com/ and yeah you have conflicting GA scripts - one from a very dodgy looking source.... adulterotic.biz
Its UA account sending data is UA-34481044-1
The UA code on your page is UA-256751-8
I suspect you are importing the GA script from an iframe or similar, or you've been hacked. Check all your external javascript calls and iframes. The dodgy GA only seemed to trigger on the homepage for me, so I guess an advert you have running there perhaps.
Get in touch if you'd like the office to look at it, or find a local GACP.
The request to GA when you visit your page is shown below (captured with
chrome plugin GA debugger)
Account ID : UA-34481044-1
Page Title : Shoe Care Products | Replacement Shoe Laces - Shoe-String Laces Ltd, UK
Host Name : shoetring.info
Page : / Referring URL : adulterotic.biz/buy.php
Hit ID : 1669827222
Visitor ID : 1009061990
Session Count : 1
Session Time - First : Fri Aug 31 2012 18:14:13 GMT 0200 (CEST)
Session Time - Last : Fri Aug 31 2012 18:14:13 GMT 0200 (CEST)
Session Time - Current : Fri Aug 31 2012 18:14:13 GMT 0200 (CEST)
Campaign Time : Fri Aug 31 2012 18:14:13 GMT 0200 (CEST)
Campaign Session : 1
Campaign Count : 1
Campaign Source : adulterotic
Language : en-us
Encoding : ISO-8859-1
Flash Version : 11.4 r402
Java Enabled : true
Screen Resolution : 1440x900
Color Depth : 24-bit
Ga.js Version : 5.3.5d
Cachebuster : 1191179120