you might have to use DEP to turn on for Divx...After several hours analyzing the situation I could isolate the problem. It was due to Theorical DivX ;-) codecs package installation I did some time ago. This package adds a lot of codecs support to your system, but it looks like it puts the files into Windows System directory. I think the preference about dll's and other related files is the own application directory, but it looks Nero was using other codes when authoring, and program crashes with Application Error, and Memory Errors.
I found the problem. By deleting this registry key:
HKEY_CLASSES_ROOT\*\shellex\ContextMenuHandlers\EncodeDivXExt
All systems are now happy. Something with the explorer plugin for DivX
encoding isn't happy with SP2.
1.. Open the System Properties control panel
2.. Select the Advanced tab
3.. Click the Performance Settings button
4.. Select the Data Execution Prevention tab from the Performance
Settings window
5.. Add Divx to the DEP exclusion list by browsing
to its installed location