Hi! I think this is one of the most confusing behaviors in Inventor, I have to admit. The reason is that when the non-Master PosRep is active, the file cannot be saved as is. Only PosRep:Master can be saved. As a result, export (as a save operation) can only happen to PosRep:Master. The workaround is to insert the assembly to an other empty assembly and then activate the PosRep in the subassembly. Then export it to an image.
Many thanks!
Johnson Shiue (johnson.shiue@autodesk.com)
Software Test Engineer