USB: scanning bus for devices... 2 USB Device(s) found
scanning bus for storage devices... 1 Storage Device(s) found

that´s the problem, i think.

try this:

Code:
fw_setenv menu_1 'setenv bootusb "run bootargsusb;usb reset;ext2load usb 0:1 a5ff0000 boot/uImage;bootm a5ff0000";setenv bootargsusb "setenv bootargs console=ttyAS1,115200 root=/dev/sda1 rw init=/bin/devinit ip=$ipaddr:$serverip:$gateway:$netmask:cuberevo:eth0:off mem=128m coprocessor_mem=4m@0x10000000,4m@0x10400000 rootdelay=6 nwhwconf=device:eth0,hwaddr:$ethaddr";setenv bootcmd "run bootusb";saveenv;front_puts SDA1-USB;boot'

fw_setenv menu_2 'setenv bootusb "run bootargsusb;usb reset;ext2load usb 1:1 a5ff0000 boot/uImage;bootm a5ff0000";setenv bootargsusb "setenv bootargs console=ttyAS1,115200 root=/dev/sda1 rw init=/bin/devinit ip=$ipaddr:$serverip:$gateway:$netmask:cuberevo:eth0:off mem=128m coprocessor_mem=4m@0x10000000,4m@0x10400000 rootdelay=6 nwhwconf=device:eth0,hwaddr:$ethaddr";setenv bootcmd "run bootusb";saveenv;front_puts SDA1-USB;boot'
then, boot with 1 or 2, please a with serial log again.