A user on the newsgroup reported that PowerPoint was hanging and locking up his PC when he saved files. He kindly reported back after he located the problem:
"It turned out to be an app called DataKeeper running in the background. We use it to make continous backups of files incase a user deletes a file or the PC goes down. It was using too much of the CPU's resources at the time the user tries to save their PP presentation. Advised user to stop the continuous monitoring of DK when using PP."