The arc lines in an image file are displayed incorrectly when you convert an image file from the EMF file format to the EMF+ file format in Windows Vista or in Windows Server 2008
On a computer that is running Windows Vista or Windows Server 2008, you try to convert the file format of an image file by using an image-conversion application. However, when you convert the image file from the Enhanced Metafile (EMF) file format to the Enhanced Metafile plus extensions (EMF+) file format, the arc lines in the image file are displayed incorrectly.
Note: This problem occurs when the arc line is drawn with the same starting point and the same ending point. For example, the arc line is a complete circle.
For more information on this issue, including potential causes, workarounds, and resolutions, see: Microsoft KB Article KB977118.