Take a look at this competitor offering
Ian. It doesn't offer nearly as much as your product but he has given its GUI an Office 2010 look. I think that if you could make KA more attractive it would sell. As it stands, Windows has been through at least 3 versions since you released KA but your product retained the look of a Win 95/98 offering. I may be wrong but my guess is that is what put people off buying it.
I know someone who might be interested in taking on the marketing of it if you are at all interested.