Currently Being ModeratedDec 4, 2011 10:34 PM (in response to Sivasiva Palani)
Have you tried the solution mentioned in this thread:
Currently Being ModeratedDec 5, 2011 10:43 AM (in response to Sivasiva Palani)
After fussing for hours, I discovered it was the presence of a QuickTime movie I had placed on one slide that was causing my grief. I removed the movie, edited the other slides without the hassle of constant saving, and then put the movie back in place when I was done.
Hope this helps others facing this saving glitch.