As with the other two crashes you reported (here and here):
It's probably caused by a shell extension, but that's just a guess based on the details known so far.
If you zip up the crash dumps and email them to leo@gpsoft.com.au I'll see if they provide more detail as to what's going wrong and how to fix it.
Please sent the crash dumps to us for investigation and we can see if there is a bug in Opus, or tell you if there is a bug in something else installed on your system and suggest a way to fix it.
(I searched my email but could not find anything from the same address as your forum account re previous reports.)