I am developing a local trail map in QGIS and I want to produce a PDF with a map insert. Map 0 has USGS layers with the hiking trails. I then add Map 1 at a larger scale with a new OSM layer as the insert. In Print Composer I see what I want - the larger Map 0 with the USGS and trail layers rendered, and the Map 1 OSM rendered insert. Perfect. I then lock all of the layers. However, the PDF I export renders both Map 0 and Map 1 with the OSM layer. Not what I want. I am missing something as I believe I should be able to do this.