That IP traces to some site in Russia. It could be anything. Personally I'd rather not wait and find out. If Norton can't detect it (which is no wonder really, it's a quite terrible AV product, use something better like NOD32!) - then to be honest I would completely re-install Windows. Drastic, yes, but at least it would solve the problem.
Get a 100% fresh Winstall on there, get some good AV solution, update them both to the max, make sure it's running balls-out clean and then start putting your main apps back on. If it starts again, one of them is infected with spyware you lucky thing.
Bite my shiny metal ass