I made an xml export from collectorz V9 and imported to XMM. As it was running all of the titles were added to the grid and I could see all of the displayed fields and the info seemed fine. When it was finished the grid became blank. The mini stat panel says imported 0 Not: 1417 and With covers: 1370 Not:47.
During the import process, three screens pop up. I had closed the 2nd and 3rd screen. Apparently if you close the 2nd panel, the scripts do not run, so nothing was imported.