If the user enters invalid music and/or playlist folders during the wizard and clicks NEXT, everything moves along happily.  Without checking the logs, his only indication that something is wrong is that the folder names are blank under Basic Settings.  It would be nice if the wizard would check that the folders exist and are readable before proceeding.  (The playlist folder should also be checked for write permissions and a warning issued if it's not.)  I suppose a blank entry should also be accepted if the user wants to set them later or has no music.