I had the same issues on a Wii I was modding today for a friend.
It was a 3.1U, but I wanted it to load backups directly from the Disc Channel. So I did the following steps.
1. Ran the Twilight Hack and installed Homebrew Channel.
2. Ran cIOS fix.
3. Updated to 3.2 using Any Region Changer and installed their "Starfall type hacks."
4. Installed Preloader 2.9.
5. Installed cIOScorp.
6. Patched the mIOS.
7. Installed cIOS Rev. 10.
8. Ran support for USB 2.0.
At first I could load up my 1 TB Western Digital Harddrive with no issues, however any backup game would cause the Wii to freeze when it was probably about to load the Banner for the game. Also if I shut off the Wii then turned it back on sometimes it would freeze right away and make a squeling type noise, not a real loud one.
So I had to use Preloader in load the HBC.
I decided I wanted the Disc channel to work over the USB port so I just reinstalled cIOScorp and the USB loader quit working, but I could then play through the Disc Channel again.
Somehow I got them both to work fine together on my Wii however, then again I think I installed cIOS rev. 9 on my Wii.