User blog comment:WolfeSpeider/Help?/@comment-1992639-20130304120416/@comment-4113369-20130305153202

Old saves just laying around shouldn't cause any problems. Data from said saves is only accessed when you try to load said save. I mean, if you wanna be on the safe side, then just go ahead and delete it (I'm not exactly an expert, to put it mildly, so this is mostly conjecture), but I doubt an old savegame is causing the problem. Have you maybe considered trying customer support?

(...Actually, does Bethesda even have that?)