My issue can't be incompatibility because all the usbs are the same model, Toshiba usbs (two 16GB, two 32GB), and one of the 32 gb and both of the 16gb have been working flawlessly (The other 32GB I bought it today) until I started to use them with Windows 7, that's when the usb problems started.
I formated one of the 32GB usb Drive (Fat32, 32KB Cluster) without fast format using the windows formater and I still got black screens or freezes. Then I tried to format the ush again using the EeaseUS tool, and when I tried to boot up a game (F-Zero GX PAL, which was working on these usbs before) I got a black screen with this text:
"An error has occurred. Shut off the console and consult the instruction manual of the Nintendo Gamecube". This USB is new bought today and it's the same model that I've been using for years.
This happened right before loading the racing track, on the main menu it was working.
This issue is starting to piss me off.