I just installed Nero’s latest release 6.3.1.17 and the problem still exists.
I unregistered the filter mentioned by Chris as the likely suspects and surprise problems gone.
If you want to try this solution go to Start=>Run and execute the following lines:
regsvr32 /u "C:\Program Files\Common Files\Ahead\DSFilter\NeQTADec.ax"
regsvr32 /u "C:\Program Files\Common Files\Ahead\DSFilter\NeQTVDec.ax"
The only consequence seems to be that Nero Vision can’t decode Apple Quick time format after this (something I can live with)
Good luck