OrCAD16.6 DRC check problem: "Net has two or more aliases"

Hi,

I have used net names of my power symbols for various pins. Running DRC I see below messages. How can I get rid of such messaes?

INFO(ORCAP-2212): Check Power Ground Mismatch
QUESTION(ORCAP-1589): Net has two or more aliases - possible short? U18,PVIN  PVIN  DDR1V8
                    SCHEMATIC1, 05-DDR2 & GP Flash  (106.68, 185.42)
QUESTION(ORCAP-1589): Net has two or more aliases - possible short? U18,VDDQ  VDDQ  DDR1V8
                    SCHEMATIC1, 05-DDR2 & GP Flash  (106.68, 175.26)
QUESTION(ORCAP-1589): Net has two or more aliases - possible short? U16,VDD  VDD  DDR1V8
                    SCHEMATIC1, 05-DDR2 & GP Flash  (241.30, 22.86)
QUESTION(ORCAP-1589): Net has two or more aliases - possible short? U16,VDD  VDD  DDR1V8
                    SCHEMATIC1, 05-DDR2 & GP Flash  (243.84, 22.86)

Any comment would be appreciated.

Thanks in advance,

Hossein