Homebrew Wad Manager 1.3 turn off my USB flash drives

[BB88]

I know topics related to this has been discussed a couple times elsewhere. I have already tried the Wad Manager 1.3 SDHC-modded version, the original version, and also Channel Manager beta 4. Whenever I load the apps, the light on my USB flash drives with be turned off immediately, and thus when I select "USB Mass Storage Device" in these apps, it will return (ret=-1) error code. SD cards work fine though.

I believe my usb ports are working since I can use them with the USB Loader with an USB external hard drives.

So does any know what is wrong? I'm using System Menu 4.0U (using Wan's updater).

Thanks!