NIS 2010 scans DVD drives when idle

I noticed my computer was making lots of loud noises and when I checked, the DVD drive was busy with random access.

 

The "Norton is performing background tasks" banner was displayed and refused to go away and the only way I could stop it was by ejecting the DVD.

 

I checked the history and it seems an idle time full system scan was being run. Is it supposed to include DVD/CD drives in this scan? If so, can I stop it from including non-fixed disks? It was really annoying!

 

Running NIS 2010, Windows 7 x64 RTM.