Currently ,You can not upgrade SAP Netweaver to 731 with RTLPOSDM. The reason is that:
The SAP POS DM 1.0 is still in the Ramp-up phase and has not yet
been released for general availability.
Target Completion date Ramp-Up: January 2013
If you would like to participate in Ramp-up you will find further
information and contact persons reference this in the Service
-> SAP for Retail Solutions
Hope it can help somebody!