Unfortunally I don't have Norton Firewall to try this behaviour, I use another Firewall and I have no issues with it.
BSplayer still tries to connect to my local address 0.0.0.0:80 when I use Pro feature "TV Tuner" but it could be that this is caused by a driver issue (I've not looked very much into this), but either if I deny or grant access to BSplayer, no other issues occour...
Does NIS tells you which address BSplayer tries to connect to? Can you tell me the exact message that you see when opening WMV files?
Thank you. Bye