I just got off a support call with Symantec. What you need to do is to exclude spotify.exe from the scan.
Run Norton 360. On the top bar (in blue) choose settings.
In there, choose anti virus.
Choose the middle tab, Scans and Risks
Second from bottom, Scan Exclusions, Click cConfigure on the right hand side
In both panels, include C:\Progrram Files (x386)\Spotify (just Program Files before Windows 7)
be sure to tick the option to include sub directories.
Then back to settings, choose Firewall, go down to spotify.exe and change the option to "allow"
(If it is not there, add it)
If spotify.exe is not in c:\Program Files (x386)\Spotify then either restore it from a back up or re install.
My spotify is working fine. I am sure Norton will get this fixed "properly" pretty soon. I can't imagine that Spotify are too thrilled about the situation!
Good Luck.