N1SDP : Ubuntu Loading Issues from SD Card.

While following the steps described in the getting started guide. 
We are stuck at a point where we are getting following error:

Booting `Install Ubuntu on N1SDP Platform'

UsbBootExecCmd: Success to Exec 0x0 Cmd (Result = 1)
UsbBootDetectMedia: UsbBootIsUnitReady (No Media)
error: disk `hd1,msdos2' not found.
error: you need to load the kernel first.\

We have tried multiple cards, with the Ubuntu flash image but we are getting the same error. 

Request you to guide on how to address this No Media issue that we are facing.