Why are you installing IOS37, 56, 57, 58 ? nobody told you about installing these IOS.
You have to install "d2x cIOS 249" only and select "BASE 56" when asked. Don't install anything else, except if it's from modmii's generated tutorial.
1- Run
d2x installer
2- Select IOS236 on the second screen "Working IOS". (if you don't have IOS236, select IOS249)
3- Then select :
* cIOS d2x v6
* Base 56
* Slot 249
4- Install.
Now stop installing cIOS. you don't need anything else.
5- Delete on your SD card all these folders :
SD:/config/
SD/apps/usbloader_gx/
6- Download USBLoaderGX 2.2 version 249 (this is the IOS slot you just installed on step 4, so this is the IOS that USBloaderGX will use to run).
7- Place the boot.dol in SD:/apps/usbloader_gx/boot.dol
8- Connected your USB drive, and run USBloaderGX
Play, enjoy, etc.
Don't install/hack/change anything else on your wii.
You didn't need anything else, it was that easy.