You may have "silent" warnings...
I've got Trend Micro (for better or worse--it's what corporate uses) on my laptop, and every time I refresh or navigate on this forum, a window pops up warning about bamrot...
Just did a scan of my computer, and it's clean...
I'm using an older version of Firefox for a thumbdrive (and yes, I scanned my thumbdrive), so maybe FF 3 blocks the site?
I remoted into my home computer and went to this forum using FF 3, with AVG antivirus running, and I did not get a warning...