I have SiteAdvisor, too, and it gives your site a green light. I also have TM Internet Security 2008 (used to be PC-Cillin), which is an awesome low-load, all-purpose suite (compared to McAfee & Symantec). TM has flagged a bunch of bad sites, but it also has blocked some good ones. I've never had it refuse to accept a site added to its "safe" list before now. I'd call them if they were blocking my site. TM supports Firefox seamlessly, but their online Contacts default to IE (Help & Chat). I assume you are a S-M business...here's their contact info:
Toll-free phone support:
Enterprise: +1 877-338-7363
SMB: +1 888-608-1009
M-F 5AM – 5PM US Pacific time, except Labor Day, Christmas Day, New Year's Day
24x7 customers please refer to your welcome email for the support contact details.
Can't wait to play with this app...will be great to catalog clips again (for repetitive eBay listings and email responses). Thanks again!