I'm brand new to PCB123 (today) but have quite a bit of experience with ExpressPCB and with Eagle PCB software by CadSoft.
In my first PCB123 project, I've run into a problem. When I specify a 10-contact connector, AWLP-10/3.2-G-R (DigiKey Part HDM10H-ND), a 14-pin connector appears in the schematic. Yet, the correct part number (AWLP-10-...) appears in the bill of materials. Also, the part number shown when I place the "cursor" on the part in the schematic is correct (AWLP-10-...), but the part shown in the schematic has 14 pins.
Other connectors in that series also show 4 more pins than selected.