Just from having it plugged in, without trying to access it?
Does it only happen if the folder tree is on, and/or when you go to certain folders (e.g. the Computer folder)?
Is Explorer stable when doing the same things?
Toggling Preferences / Miscellaneous / Advanced: mtp_enable may help. (But if not, please reset it back.)
If a crash dump was produced, please email it to leo@gpsoft.com.au and I'll see if it indicates what might be failing, and whether it's something within Opus or a 3rd party driver or shell extension.