Rachel,
Ready for some bad news? It means that the spiders crawling your site have found links to your site that are from low quality (trust) sites. Hence if you have low quality sites providing links to your site it could bring down your trust.
We both hope that these are not your doing. What that means is that just going out and soliciting links to your site, without first checking out the domain trust, content, and page rank of the site you are trying to receive a link from, you may just be asking for trouble by accepting just any old link.
So if that inset bad enough here is even worse news! Rouge websites could possibly provide a link to your site just to do evil deeds to your site. Its worth checking into where the links to your site come from. Here is where the link disavow comes into play.
I am not saying that is what happen in your case, so please check it out instead of ignoring it, and hoping things will improve in the future.
Wish I had better news for you,
