A possible way to import saves to VMCs?
I think I may have a way to copy .psu saves to Virtual Memory Cards. I think it could be done, by launching an .iso file with uLaunchELF (or any memory card manager that can import saves (if there is any)). But so far I was unsuccessful with it. The image downloaded from sksapps crashes at white screen. I then tried to modify a game image and change it's executable to uLE. Still no success (game booted, but it hangs at black screen and nothing happens). Last try was to modify a multi-elf game (like Age of Empires 2) and change any other ELF than main exec. It also didn't work, but that may be fault of AoE2, with doesn't work with my USB dongle (forgot to mention, I'm using USB for all this), as it crashes after chosing language (it loads a different ELF at that moment).
Since I only checked it with official 0.8 release, I wasn't able to try running this on any SVN version, so could anyone check if it would work with newer revisions?
Bug in uLE VMC driver prevents safe delete or overwrite.
I've now tested your files and determined what the problem is, and as you can see from the title of this post it is due to a bug in the VMC drivers of uLE. This bug affects deletion or overwriting of existing files/folders, which is the reason why your attempt to psuPaste that PSU file into that VMC failed, since it already contains a gamesave with identical folder name.
Unfortunately this means that uLE is not fully capable of being used as a backup+restore tool for individual gamesaves. Backup to PSU files works fine, but restoration only works for gamesave folders that don't already exist in the VMC.
Thus you can backup an entire VMC to PSU files, and later restore all or part of those files to a clean new VMC. And you can also restore a PSU file from elsewhere to a VMC that doesn't have any matching folder. But you can't update an existing gamesave in a VMC file by psuPaste (like when you need to back to a previous game chapter), since that would require an overwrite, and would thus trigger the bug.
The above means that you should NOT use uLE v4.42a (or older) to delete any gamesaves in a VMC, nor to overwrite any existing gamesave in a VMC, since either of those operations could corrupt the VMC content.
Btw: I found two 'suspicious' folders in that VMC, containing zero-sized files with weird names. The folder names are quite normal though, being "BESLES-820421G000001" and "BESLES-820421G000002", which should be gamesaves for the Euro release of "Metal Gear Solid 3: Subsistence". The problem of those files may be related to another known uLE bug, which fails to properly copy gamesaves containing zero-sized files. I mention it here mainly to make you aware that those two gamesaves are invalid on your VMC.
I am now going to spend some time searching the source code of uLE for ways to fix these bugs, and when that is completed you can expect a new uLE release. But I'm not promising any specific ETA for that...
Best regards: dlanor