In the Score Manager, check to see if the Perc MIDI Map column is visible in the top box - right side. If it is visible but the map names are italicized select them again to match the maps listed or the the ones you wish to use. Then below, Notation Style should be set to Percussion, click the Settings button and select the notation layout for the MIDI Map you assigned above.
If you don't see the Perc MIDI Map column, click the drop down for Customize View and select Percussion MIDI Map. The column should now be visible in the upper window.
iMac i7, OS 10.8, 10.9, W7
VDL2.5.5, Finale 2010-14
Kontakt 4-5, various other soft synths