The one page I'm getting the warning at indeed does have the Nimda appended tag at the bottom of the page, i.e. no false alarm here.
Thanks for taking a look.
I guess it depends on one's definition of a false positive. In my opinion, detecting leftover traces of a
defunct threat is of little use to the user, and clearly constitutes a false positive. I think such detection is actually a disservice in that it flags sites that no longer have a problem, while creating an ongoing problem both for the visitor and the webmaster. Users have to treat the threat as real -- and it isn't. How much more
false can it get?
I contacted rotowire and received a reply from their editor saying that at one point they were infected with Nimba, although the virus has long been eradicated. However, the virus left traces (html) of its presence that remain on some files, predominantly error message files. They are trying to track down the remaining traces -- because they understand that "[such] traces are an inconvenience." Avast! needs to come to a similar understanding.