UPDATE: To readers arriving here via Google: this is a post from February 2011. However, as I write this in January 2015, Microsoft PowerPoint 2011 for Mac again is crashing frequently. I recommend saving your work often. I corresponded via Twitter with the Microsoft support team and they pointed me to their general cleanup suggestions here (basically removing all your preferences).

Want to try out an alternative to PowerPoint? Request a beta invite for the new presentation design software SlideMagic here!

Here is the original post from 2011:

OK, more searching solved the issue, which can be found here: http://support.microsoft.com/kb/975723 My toolbar folders were corrupt.

Everything is working again without toolbar customization. But when I start modifying the toolbars again (I need a set of 20 buttons or so to be really fast an efficient in PowerPoint), the whole saga starts again. I will keep you posted about my experience with Microsoft PowerPoint 2011.

I have been battling with PowerPoint 2011 for the Mac for the past hour and it seems seriously flawed. When entering slideshow mode, it just crashes. Searching online for a solution reveals dozens of forum discussions about the same issue that are unresolved. Do not upgrade from Office 2008. Repeat, do not buy it, it is not stable yet! Usually I am an early adopter of software and can live with a few bugs here and there. Not being able to go into slideshow mode kills the purpose of PowerPoint, this is a serious flaw.