Does anyone know what the problem is?

I rendered an avi as an mpeq1 file. When I inserted the file into PowerPoint, I get the message below. I'm using V4.0b (Build 174). This never happened when I used V3.0. I rendered multiple files into mpeq1 and when I tried to insert, I got the message below.
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PowerPoint found an error that it can't correct. You should save presentations, quit, and then restart PowerPoint.
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Thanks,
Gil