When I do a search through DO and do a simple find to find some files (*.mxm) in the media folder of my Samsung Galaxy S2, DO does not find anything even though I know the files are there. The search is set to simple, wildcards are checked and no filters are on.
When I do the search using win explorer, the files are found no problem.
Are you using Opus's own Find functionality (Tools -> Find Files) or the Windows Search functionality (search field, top-right of the window similar to the one in Explorer)?
I am beginning to suspect Samsungs driver - as although I can find the files using Win Explorer, I cannot delete multiple files at once - only one at a time. Still, that does not explain why I cannot find them in DO mind you
Is it a real folder or some kind of virtual folder?
(e.g. Does it have a drive-letter that you can access and list the contents of via a Command Prompt? Open a Command Prompt via the Start Menu, then type "dir x:" where x is the drive-letter, assuming it has a letter at all.)
I suspect Opus only supports searching real folders, but I don't know for sure. Contact GPSoftware Support (link in my signature) if you want a definitive answer.