I don't know, but I REALLY hope they don't do that for MK9.

It's a glitch
For some reason the save file gets corrupted and causes that loop to happen. If you have problems with playing arcade, I wouldn't suggest completing the kombo challenges until you've deleted your save file.

I had a corrupted file and had to complete the kombo challenges twice in order to get the supreme champion trophy because the game didn't register all the challenges as being complete.

That's because you have to complete the kombo challenges using a P1 controller or else it will not register.

also if you turn off the system before going back to the main menu, you will have the trophy/achievment but it will not save them as being done. good to make sure you go through and check every character to make sure, once again.