Robert_Charlton - 4:13 am on Nov 13, 2012 (gmt 0)
...so we decided to set up a little network of our own...
Trisha - Apart from the links from the member with the hidden text etc on his site... it's possible that Google might see your "little network" as manipulative.
What percentage of your backlinks would you say came from within the network vs from outside the network?
Did you and the other bloggers also favor each other with anchor text in your links to each other?
Take a look at...
Google Webmaster Guidelines
...and particular at the section on linking...
Any links intended to manipulate a site's ranking in Google search results may be considered part of a link scheme. This includes any behavior that manipulates links to your site, or outgoing links from your site. Manipulating these links may affect the quality of our search results, and as such is a violation of Google's Webmaster Guidelines.
You suggest in your post that you once upon a time hung out at various SEO forums, so you may not have been completely naive about the importance of backlinks to help you rank. I'm guessing that much of the information on the SEO sites you've seen, though, emphasized only the manipulative aspects of linking, and, if so, that may be unfortunate for you now.
In the disavow file, I'd keep comments and excuses as short as possible. You might also want to double-check whether you've included all the links you should be disavowing. I myself would assume that if you did have a small, closed group that interlinked, those links could well be counted against you, but they might not be. That's the very tricky area in using the tool.