**BUG** Concise problem statement: I get repeat reference number assignments if I add a normal part after adding a couple of parts of a multi-part item Steps to reproduce bug: 1. Create a multi-part schematic item. I used a 7474 2. Add the .1 and then the .2 sub-parts to a schematic - They will be U1.1 and U1.2 respectively 3. Add a normal part, say a 74597 to the schematic. It will be U1 Results: The normal part has the same part reference number as the sub-parts of the other part. Expected results: The normal part will have the next reference number available. Browser: Chrome Version 45.0.2454.93 (64-bit) (Mac OS X Yosemite)