big gaps in music for windows DVD maker

I have photos loaded in WDVDM, and have selected music files added, but when
previewing, there is a gap of several minutes between music selections, as
the photos continue to change. Any suggestions would be much appreciated,
very frustrating, thank you, Steve g

PS, all music files (eventually) play ok, and by switching the order,
whichever is listed first starts right up, but again a big gap after it
finishes