I'm using Vista Ultimate 64-Bit, and Opus 9.1.0.0
Sometimes, when I click on a file, Opus crashes.
This mainly happens when I want to move the file to another directory, using dual pane.
Perhaps the following is not a bug, etc. When I right-click a folder and select Search, the default Vista search dialog appears. On my old XP machine, the Opus search dialog appeared.
Please follow the steps in the FAQs on diagnosing crashes and let us know what you find. Just knowing the program crashes doesn't give us any clues about what is causing it (which is often a 3rd party shell extension or codec).
If you search for "vista" and "search" then you'll find several threads on the subject, like this one.
Also, please read FAQ: Ask one question per thread.
I did read the FAQs, it only mentions crashes/exits when right-clicking a file. This is a normal left-click to drag a file to another window, or even just a normal left-click on a file. DebugView doesn't produce anything in this case.
Apologies for asking 2 questions in one thread. Thought I save some extra pages/topics.
Which lister format are you using ?
Are you using single click settings ?
What type of files? Any?
Where are you dragging the files to ?
Dual pane, each pane with it's own folder tree.
No.
Any type; txt, archive, any.
I don't neccessarily have to drag it anywhere. Just left clicking it and attempting to drag it anwhere, is enough to cause a crash. However, if right-click a file, display the context menu, then try to drag it with left mouse doesn't appear to create a crash.
Like I said, this is intermittend. It'll prob work ok now for the rest of the day until sometime later when it crash again.
9.1.0.0 is quite old and did have some x64 problems in it including a crash just like the one you're describing. You should update to the latest version.
I just noticed you said Opus 9.1.0.0
The bug you're experiencing was fixed back in January. Why are you using such an old version?
(Edit: Posted at the same time as Jon. Didn't meant to duplicate what he said.)
Oops 
Thank you, downloaded the latest version.
Well, you could defend yourself and say that you flagged up the "ancient version" in your subject, the bit that people often overlook when reading messages.
Is it DOpus's rather clunky "update" alerts that prompted you not to use it?
Tell it to "Update check silently" – another fine tweak buried in the complexity – and you won't get left behind again.
The ancient version comment in the subject was my doing.
I suspect many people using such old versions are doing so due to being unable to find a newer, working crack than due to how good the update checker (which works just fine unless you're behind a corporate firewall) is.
Either way, it's common sense to check for a new version before looking for other solutions or asking for help when it's such a long time since installing an update.
I admit that it is common sense to check for a newer version if running into problems, and in this case I did not do so.
However, all installed applications on my PC which have update checkers, auto update, etc, have those options disabled where possible. Not because of so called cracks (incidently, I'm not using a cracked copy of DOpus), but because updates can break what was a perfectly working application. This happened to me more than once, and I had to revert back to an earlier version. Even my Windows automatic updates are turned off, it is set to notify me of updates and let me decide. You may be aware of the update Microsoft released, which stopped ZoneAlarm from working. ZA had to release a fix to repair Microsoft's update. This applies not just to commercial applications, but freeware as well.
According to the file naming convention, releases prior to 9.1.1.0 (9.1.0.1, 9.1.0.2, etc) are classified as minor updates. 9.1.1.0 appears to be a major release, since it skipped 9.1.0.7 - 9.1.0.9. I'm updating, as this may fix my problem.
DOpus is complex, and often it is easier to ask rather than to read the manual or support forums. Too many times I have read the manual and thought "what!". Bring back the days of printed manuals lol, they were a lot easier than PDF's.
Why don't you print the pdf? 
I don't have anything (that I can control) set to install updates either, just to notify me when they're available. That way if something goes wrong I know why. I almost always update stuff though.