If a crash dump is created matching the date & time of the crash, you can email it to me (leo@gpsoft.com.au) and I'll see what it shows.
The problem is most likely a shell extension that adds to the Properties dialog, crashing when called by Opus. ShellExView can be used to view and disable shell extensions to track down which one is doing it, but the crash dump may pinpoint it quicker, so let's try that first.