lol platanos. that is asked too much 
i dont know of any (recommendable) mp3 music tagger which also reads or tags AVI videos. those mp3 tagging tools come with fine status bars ... but with .AVI's, no chance! i am not going to recommend now some competitive file manager (other than Dopus) or else leo will be beating the bsh out of plunder me 
ok Plunder, don't worry. Thanks anyway.
I'm not personally trying to get this fixed. I was just testing it out since I had nothing else to do 
For me, it also doesn't work under Large Icons, Small Icons and Thumbnails.
I'm testing with all kinds of video files with folders that have either 1 file in them or hundreds.
If it previously added up the times and you switch views, it looks like it's still working. Hitting Refresh makes it all reset and never adds them up like in the working Views.
So the Views that don't work for me:
Large Icons
Small Icons
List
Thumbnails
All other Views work for me. Which of course are:
Details
Power
Tiles
@Leo (or anyone else testing), Are you hitting Refresh after changing to a non-working View?
I set the lister to open in List mode, then restarted Opus, opened a new lister (in List mode), changed to the folder containing the avis, and the counts worked okay for me.
If either of you want to create a config backup (Settings -> Backup and Restore) and private-message it to me, I'll try loading that and see if I can repro the problem then, and if so work out what's triggering it. (Don't attach it to a public message, in case it contains anything you don't want shared. Also, zip the backup file so the forum accepts it.)
Ok PM sent, thanks Leo.
Just tried that and it didn't help anything.
Platanos just sent his config so I won't for now.
@Platanos, Does the total counts work for you in Large Icons, Small Icons and Thumbnails?
Yes ktbcrash, it works for me in every view mode. It only doesn't work in list view.
haha. My install/config works worse than yours then 
Jon says it depends on which columns are included in the folder format. If any column is included which triggers metadata calculation (e.g. Duration or Description) then the status bar will show the info.
This is even though List mode doesn't show those columns. They just need to be 'turned on' to stop the metadata calculation being skipped, at least for now.
Thanks Leo and Jon. All Views work now when adding "Description".
I personally only use Details and Thumbnails but had to report that they are all working. It's also nice to know they will work if I ever do change Views.
Thank you both very much. 