Polygon fill colour covers entire background in exported map.

[MJChurchill]

Hello,
I am wondering if anyone else has encountered the following issue:

I have a polygon layer in ArcMap with several classes. One of the classes is symbolized with an outline and a simple fill, the rest are symbolized with an outline and no fill. Transparency for all layers is set to 0.

In the ArcMap window the data displays as it should with the background white and the filled polgyons grey:
[ATTACH=CONFIG]26122[/ATTACH] 
However, when I export the map (I've tried exporting as .jpg and .pdf), it makes the background the same colour as the filled polygons:
[ATTACH=CONFIG]26123[/ATTACH]

If anyone knows how to prevent this from happening, please let me know.
Thanks,
M.J.

[AdamGuo]

Make sure the "Clip Output to Graphics Extent" is not checked and also under the 'Format' tab make sure your background color is either 'No Color' or 'White'.

[ATTACH=CONFIG]26128[/ATTACH]

FYI- Your question is in the wrong forum.