Hacking Wii iso not working

[smithy311]

Hi i have been downloading isos for almost a year now and i haven't had many problems. but now every iso i have downloaded and burnt to disk wont play on my wii. i cant see it being a coincidence. i am using the same burner as always and the same disks as usual but i am having problems. my wii wont read them but it reads my old ones. i have a wasabi chip and priiloader. any help would be great.