I suspect your wii is ok, but who knows.
What preloader/priiloader version do you have installed?
What preloader/priiloader system hacks do you have enabled?
What is preloader/priiloader set to boot to?
What is preloader/priiloader set to return to?
Have you installed a dol/elf into preloader/priiloader? If so, what?
What system menu are you running?
What system menu version is displayed in preloader/priiloader
What ios is displayed in preloader/priiloader?
In preloader/priilaoder settings, what ios is used, system ios, or other?
Have you had this trouble with usb loading, disk loading, or both?
What about originals?
Can you reproduce this error consistently, or is it completely random, regardless of what you do?
While your at it, you may as well run dop-ios-mod v11.5, with ios249, scan your wii and post the cvs report here.
Off to bed now, talk later.