Due to unforseen mechanical issues involving the launch vehicle hydraulic system and exhaust ducts, the launch date of AubieSat-1 has been postponed until October 27, 2011.
More specific details about the problem can be found at http://www.nasa.gov/mission_pages/NPP/launch/index.html
Original AubieSat-1 Launch Information http://www.uk.amsat.org/2011/09/30/aubiesat-1-launch-information/