Access denied to folders in external hard drive

I am running Vista Home Premium, on a Dell XPS tower. I have an external hard drive, a WD MyBook that I have been using for more than a year to back up my files weekly using the Microsoft program with Vista. I also direct to that drive My Recordings from  Windows Media Center. For the past month or so I cannot do a backup because I get a message that access is denied or convert any files in My Recording folder unless I disable Norton Security Suite Anti-Virus and Smart Firewall.

 

After I do the disable I can do the backup OK and work with  all the other files. I do not think I have changed any settings.

I am running Vista Home Premium, on a Dell XPS tower. I have an external hard drive, a WD MyBook that I have been using for more than a year to back up my files weekly using the Microsoft program with Vista. I also direct to that drive My Recordings from  Windows Media Center. For the past month or so I cannot do a backup because I get a message that access is denied or convert any files in My Recording folder unless I disable Norton Security Suite Anti-Virus and Smart Firewall.

 

After I do the disable I can do the backup OK and work with  all the other files. I do not think I have changed any settings.