Thanks for the crash dump files.
They point to a component which is loaded into the Opus process corrupting the shared memory heap. Unfortunately, all the crashes are in different places, with the only common thing that they all seem to happen when calling into the Windows shell. So the dumps don't suggest a particular component is at fault, but it is highly likely that it is a shell extension that is causing the problem.
Using the ShellExView method I mentioned above is the only real way to track down what's causing the problem. I've updated the Crash, exit or high CPU when viewing certain directories FAQ with a slightly more detailed description. That post also has a list of shell extensions which have caused problems in the past and may be worth disabling first, if you have any of them.