It sounds like your softmod is a little unstable, it could be one of the older versions (they're pretty baked-in nowadays so an update should do the trick) or you have "stubbed" IOS files installed.
1. Grab ModMii. Use it to download: WiiMod. cIOS222, 223, 249 and 250. Wiiflow or USBLoader GX (or simply use the ModMii update wizard to update the entire Wii)... Copy the "COPY_TO_SD" folder to your SD card.
2. On the Wii, open WiiMod. Use it to delete IOS222, 223, 249 and 250. Then use it's wad installer to install the cIOS wads (you're replacing stubbed Nintendo system files with hacked ones - it's probably your loader trying to use stubs that causes the hang).
3. In your loader, use cIOS249 by default. cIOS250 for CoD. cIOS222/223 for stuff with additional peripherals (Rock Band, Animal Crossing)
I only recommend Wiiflow (my personal fav cos it looks great) or USBLoader because ModMii will update those for you. You could update Config USB manually though, they all load the same cIOS files.
Another possibility is the format/layout of your USB drive. You can have as many partitions as you want but I'd recommend keeping your game partition in FAT32 format (use a program called FAT32 Formatter) and making sure it's the first partition on the drive. If you're currently formatted as WBFS or NTFS you can extract the game files to your PC using Wii Backup Manager, reformat the drive then transfer them back.