For the next half-hour or so, I will be trying to convert saves manually. The bug will *most likely* be found before 6am EST. Til' then, good luck.
UPDATE -The problem has been fixed... read on.
As I had earlier suspected, the GUI is very necessary for encrypting/decrypting VMC files... Why this is, I have no clue. It's very annoying I also converted the XPS to a PSU with the PS2save converter (ps2savetools.com).
I'll just release a new version of the tool. I just loaded up the game without the black screen error; but I think the savegame may be encrypted with some shiz, so I can't completely "load" it.
Maybe it's corrupt from copying it over from my old PS2, so I'll find a regionally-correct save from online. As always, thank you for using my tools!!
UPDATE -I successfully loaded a 100% savegame for Cars.
You must convert your XPS to a PSU
You must use the original GUI by Aldos and ps3dev-net
As to the corrupted save for the Cars game, I think that the "Preserved" attribute (0x0080) must be a result of improper copying from uLanchElf; MAKE SURE YOU USE mPaste... I will be releasing v3.5 shortly.
Version 3.5 is almost out, with some major cleanup; I found the errors.