Couple of thoughts come to mind. My netbook does not have a boot option to recognize the sd card slot as a boot device, so I have to use the usb slots. So just to be safe I would advice the usb slot.
unetbootin can be used to make a bootable usb of the vl7.0live iso
, but it does not work for the installer iso.
I recommend the installer iso
this one, in most cases but you would need to follow the following tutorial on another linux box to create it. http://www.opensourcebistro.com/blog1/?p=704
If the live iso is your best option then put it to a usb stick with unetbootin as you did before and follow this tutorial for installhttp://www.opensourcebistro.com/blog1/?p=712
Of course you will need to make sure your bios is set to boot from the thumbdrive, first.