Purchased song won't play full length

I am making a retirement slide show for a co-worker and purchased an instrumental version of In My Life, which has a running time of 3:11. I have approximately 20 images. THis slideshow is for private use and will not be uploaded or shared online.

WHen I drag the song over, it trims to 2:54, effectively cutting off the last notes which are naturally sustained as most endings of songs are. I've not been able to figure out why I am losing these last few seconds, as it is the closing piece to a larger overall project. It ends abrubtly

Using iMovie 11