The signature that has the problem is 31.3.5417 dated 31/12/07
If you're running Internet Explorer, then you may see an alert for an individual .js file as above, in a Mozilla-based browser (such as Seamonkey or Firefox) you may get a virus alert for a file named something similar to C:\Documents and Settings\USERNAME\Application Data\Mozilla\Profiles\Default\xxxxxxxx.SLT\CACHE\xxxxxxxxxxx
Usually, these false positives are fixed by CA pretty quickly. For most people this should just be a temporary nuisance that will be fixed with the latest virus update.
You can submit suspect files to CA here for analysis, that may well help them to fix the problem.