Just got the latest 1.1.1 –
Using a Kingston 16gb DataTraveler DTI/16GB
WiiMC worked well without IOS58 though it had severe buffering fits with some files larger than 1.4 gb
After installing IOS58:
Versions 105-107 would play my few test files flawlessly but would freeze the Wii when I pressed the Home button
Versions 108-111 would go to a screen dump in about 3 to 10 seconds then freeze the wii
Both situations required holding down the power button.
Update: I tried v104 and it worked without any problems. Sweet !
Update 2: Deleting in meta.xml in the wiimc folder fixed my v1.1.1 problem!