Crystal 10.2 came out long before Office 2007 and so it was never tested with it.  Also, there are some internal structural changes to many of the file types in Office 2007.  I suspect you're running into a conflict with Crystal exporting it in the older format and Office 2007 expecting the newer format.  If you can open the file after export, this is something you're just going to have to live with unless you can upgrade everything to Crystal 2008.