Help music syncing


i used doubletwist for mac to sync about 160 songs to my phone.
the program downloaded 160 or so songs, except some of the songs were downloaded 2x. The songs that did not download were the 25 or so songs that i purchased through itunes without their new "itunes plus" fee. Does anyone have any suggestions for getting the right music to sync other than paying apple the extra 30 cents?