Ppt animations working perfect; now off & can't figure out why

Ppt 2007 - New Laptop Vista. 4G RAM.. Created Missions slideshow. Includes:
custom animations on photos and/or text--all in sync with different music
clips,and slides have diff. timing for transition. Even has 2 movie clips
included. Have shown it over a dozen times in past 2 months. Has always
worked perfect. Today, ALL slide transitions & custom animation timing is
off--very slow to change. Even a :01 sec. black slide take 7 sec. before the
slide moves. I timed the different sections. The music clips play the speed
they are suppose to, but the slides don't match up anymore. One section is
01:37 in length--music wise. It took the pictures another 01:08 to finish.
Played other Ppt shows that were perfect--they're not right now either. No
new software added to laptop. Any thoughts what's causing animations to slow
down?