My assumption is that something bad is going to happen, so if it were me I'd back up my documents, configs (such as .ini files associated with the settings of software I use a lot - WS_FTP folders, DreamWeaver sites, Command & Conquer preferences etc), bookmarks and so on, then reinstall.
Assuming I couldn't fix the problem of course. If it is an ubernasty, there's a good chance it disabled part of Norton when it first ran. Try suspending Norton and using a fresh install of a different A/V.