my ISP is using mcafee, which apparently is marking your site as "dangerous". I'm not 100% sure how they are doing this, I assume something during DNS lookup.
You might want to talk to Mcafee about their classifying your site as dangerous, or just curse them out like I've done when they listed my software as malware. For what it's worth, they do the same to emacssurvey.org so it's not just you :)