Marker fill option not retained.

hi,

i have observed in the excel 2007 that when you are creating a radar
chart(Spider) with some data and plot that on a chart sheet. and try to edit
options by clicking on the chart and selecting format data series in the
options on the left select marker fill option you have options(solid
fill,gradient fill,picture or texture fill, automatic etc,....) select
gradient fill .once selected the chart is filled with a gradient color, click
the close button at the bottom right and save the excel and close the
excel.again open it and you navigate to the chart and select format data
series. and select marker fill. notice that the option that was
selected(gradient fill ) is not there but it is reset to automatic.

is this an issue with the excel 2007 or am i doing anything wrong that is
not retaining the option after saving it?

looking forward for a response.

Regards
Raghavendra.