I don't know what the problem is, but the easiest solution would probably be to copy and paste into Word (which I guess is how you produced your attached image file).
If you are saving as an xls you might try changing to one of the new formats, could help.
Just in case you haven't found the "copy as picture" command in 2007, it's buried under the paste menu!:
IRstuff - that's the point of the "Copy as Picture" menu. It gives you the option to "copy as printed" so you can get an image without the grid lines without having to turn them off and on.