i have done a ls in /dev/block. it is sda, not sda1.I used "mount -t vfat /dev/block/sda1 /mnt/sdcard/usbStorage" before I started using StickMount, so try that. The issue in your command was the "sda", new devices appear as "sda1", "sda2" and so on.
i am not sure what is wrong with my 4.0.2 the mount just doesn't seems to work. i will try a system flash again to see if it helped
because i got the same error message with my cifs.ko.