Microsoft Powerpoint - "PowerPoint found an error that it can't correct. You should save..."

I'm trying to save a PowerPoint Presentation.  I am using Microsoft Office PowerPoint 2007 and Windows XP Professional.  No matter how I try to print or save my presentation I get the same error "PowerPoint found an error that it can't correct.  You should save presentations, quit, and restart PowerPoint".  Is there any way I can I can solve this problem without having to close out of PowerPoint and losing all of my work???