I want to delete files that have the archive attribute set to off but not any parent folders.
This seems really easy but it's not working.
I've got:
Subclause Match
Attributes Match OFF: -A
AND TYPE MATCH [FILES ONLY]
Doesn't work. It deletes the file only when the attribute is set but also deletes the parent folder if there is only 1 file in the folder.
I've also tried it without the Subclause Match statement. Same results.
What am I missing here? I'm using 9.1.1
Seems fine to me using Opus 9.1.3.0 and the filter shown below. If the same filter doesn't work for you, try updating your version of Opus.
(There have been 10 updates & 10 months since 9.1.1.0.)
When you only had 1 file in the directory and you deleted the file, did the directory remain?
The file deletes for me too but so does the directory. If any files remain the folder doesn't delete. Only when the folder is empty does it then delete the folder.
NOTE:
I am selecting the folder in the tree pane or on the right side of the screen and hitting the delete key.
I don't want to highlight all of the files because I'm trying to clear out files from a nested tree structure that I want to remain in place.
Is there some reason you can't upgrade to the latest version?
I backed the version down because I was experiencing another bug where I could not drag and drop photos from a web browser into dopus.
That works fine in 9.1.1.
So I'm wondering if it's a version thing or I'm doing something wrong?
If it's Firefox then it's probably the old bug that's still in Firefox's drag & drop support (unless Firefox 3.5 fixed it; I haven't checked) and affects all versions of Opus as well as Explorer and Total Commander... The bigger the image the more likely the problem is to be triggered, and it's 100% Firefox's fault (I've investigated it under a debugger and put the proof into Mozilla's bug database, here, FWIW).
If it's another browser, not Firefox, then I'm not aware of any similar problem reports.
Edit: Added link to Bugzilla report.
I'm running Firefox 3.5 and DO 9.1.3 and i can drag images from the web with Firefox and drop in a folder.
I just dragged the forum logo from here, and dropped it in a folder. It altered the name and filetype to .bmp not sure why but it worked ok.
It works sometimes but not always. (Unless it's been fixed, but the bug is still open so I expect not.)
Basically, Firefox tells whatever you drop on that the file is there before it writes the contents of the file. There is then a race to see if Firefox can write the contents before the program you dropped on tries to read them. Sometimes it works, sometimes the reading program gets an empty or incomplete file.
I've dragged about 50 images out and in to Opus now without error ranging in size from smileys to widescreen wallpapers. The only negative is the images are converted to .bmp and the filenames are changed to random strings each time.
For example your Pretentious Name logo in the bug report, the background gets changed to black and the quality killed due to the .bmp conversion.
I even opened Photoshop, dozens of FF tabs and kicked off an antivirus scan to "bog down" my computer hoping to slow down Firefox from writing the file to reproduce the error.
So it's either fixed, or i'm lucky. 
If the images get converted to BMP it usually means they didn't get fully downloaded by the browser for some reason. Odd if that happens all the time, though. That definitely doesn't happen for me (the image is saved in its original format unless the data from the web server was incomplete or partially corrupted).
Any thoughts on the deletion of the files without directories?
When you only had 1 file in the directory and you deleted the file, did the directory remain?
The file deletes for me too but so does the directory. If any files remain the folder doesn't delete. Only when the folder is empty does it then delete the folder.
NOTE:
I am selecting the folder in the tree pane or on the right side of the screen and hitting the delete key.
I don't want to highlight all of the files because I'm trying to clear out files from a nested tree structure that I want to remain in place.
From the folder tree it does delete the folder as well, but not from the file display.
Please update to 9.1.3.0 as it just makes things more complicated if you're using a version that's almost a year old.