I was having issues of DO displaying thumbnails of images and in particular images from my iPhone. I would select View Mode | Thumbnails, but it was only showing some thumbnails and generally these were for pretty old files and nothing new. So, I tried using Windows Explorer and it wasn't showing them to. I searched for issues with Windows Explorer and thumbnails, which the following resolved my issue in Windows Explorer:
In Windows Explorer, click Organize / Folder and Search options / View Tab. Remove the Check Mark from the Always show Icons never Thumbnails option. Click Apply / OK.
Surprisingly, this resolved my issue of DO not displaying the thumbnails either. I find it rather odd, perhaps it is just me, that a setting in Windows Explorer was affecting how DO operated. Is this by design? Also, what I find irritating is when I jump around using the scroll bar or mouse wheel. DO does not seem to be smart enough to fetch the preview for the current files being view, but it caching them one-by-one in seq. This can take some time to cache if there are a lot of files.
Secondly, I have noticed that with newer version of DO that accessing the files within my iPhone appear to be slowwwww. I can select a few files, right-click to select an operation like "cut", and the program will take a long time to react. The little circular busy icon is display and the DO window goes gray. This process can take up to a minute or more depending upon how many files I select. Once right-click content menu is shown and I select and operation, it take DO a period of time to process whatever it is processing. Now, I have noticed this process it a bit faster now that I have unchecked the "Always show Icons never Thumbnails" option. Any reason why this is the case?
If you have Opus's MTP support turned off (by setting Preferences / Miscellaneous / Advanced: mtp_enable to False) then the display of portable devices is delegated to Explorer, which explains why the thumbnail setting seemingly affects Opus as well.
In this mode, file handling is also performed by Explorer and not Opus - so selecting files, right-clicking, copy & paste, etc, are not under our control.
If you set mtp_enable to True then Opus will handle portable devices itself.
Sorry for the delay. I did check the setting and "Miscellaneous | Advanced - mtp_enable" had a value of "True". I assume this setting is set by default? I don't ever recall changing this setting either to True or False.
Perhaps it is how my computer is set up? I am running Windows 7 64-bit. What is a little bit different on my system that I have my system set up sort of like the old style of Windows XP. I have UAC turned off, I have an admin and two user accounts. I normally run using one of the user accounts. Could this cause the problem I was seeing?
The question now is if "mtp_enable" was set to True, why did the change to "Always show Icons never Thumbnails" affect DO then? Also, why is DO so slow while accessing my iPhone at times? I don't recall this behavior prior to the 10.5 release.
I don't know. It could be a complete coincidence, or that Explorer was tying up the device in some way with the icon/thumbnails setting in one mode but not the other, or perhaps Opus is unable to get thumbnails for the files itself for some reason and it is falling back on the shell to get the thumbnails, or something I haven't thought of.
Prior to 10.5, Opus always functioned as if mtp_enable=False. (There was no setting; Opus didn't have its own MTP code so it could never be enabled.) Now Opus uses its own MTP code by default, but lets you fall back on the Explorer code in case of problems like this one with some setups.