Hello,
I don't know the setting of the DVD-Burner, because it is installed by Factory (I have two optical drives) I think this should not play a role for any virus scanner.
Maybe my neighbour has the same problem on another PC. I will check in the next days. He told me yesterday on 10:30pm that he has no possibility to burn a cd. He uses avast home edition, as me too. The Operating System is a fully patched windows XP home (SP2).
With former Versions of avast everything worked well.
I may try the settings as described above. Standard shield uses the setting "standard")