and this is the method you used ?
Creating a USB flash boot drive
As the Installation Manual states: "The easiest way to prepare your USB memory stick is to download hd-media/boot.img.gz, and use "gunzip" to extract the 256 MiB image from that file."
This method temporarily limits your memory stick to 256 MiB but it is simple to get working. You can chose to re-partition your memory stick once you are done installing Debian with it. To keep the memory stick, (hereafter called a flash drive) in its current size and still have the installer on it, follow the Formatting your drive with additional software for booting directions below.
Before you put the boot image (boot.img) and the netinstall image on your flash drive, make sure you have a recent backup of your data, both on your flash drive and on your Acer One. First find the device node of your flash drive on the command line (press Alt-F2 to bring up a shell on the Acer One). Note that using the wrong node will destroy data on that node. Assuming your flash drive is /dev/sdz, execute this command as root:
# zcat /path/to/boot.img.gz > /dev/sdz
Afterwards, mount the flash drive and copy over the net-install ISO file.
I had no trouble getting this method to work with my AAO..
are you getting any errors when copying the iso to the USB flash drive ?
After copying the iso file over does it appear in the directory listing ?