An internal application error has occurred

We get the same kind of interferrence with the corporate edition of Symantec 2005 (newest Norton here) and did not have this problem before then. It happens at irregular intervals at any of our public systems all over campus (I provide support). If it were mine I would expect Norton (Symantec) to fix your problem or refund your purchase. If you bought by credit card, has the bill arrived and did you yet pay for it? If you did not pay yet, then your credit card company should provide leverage for resolving the problem(s). I know you would probably rather that it just work.
For myself, I would totally uninstall the Norton and put up Avast (free for home use) and perhaps something like the free Zone Alarm. Just a personal opinion.