Excel 2007

I have conditional formatting set up in certain cells. "Rule Type" is
"Format only cells that contain". The "Rule Description" is:
"Specific Text...containing...[a certain word]". When I click the
"Format..." button, the usual Format Cells dialog appears.

On the Font tab, the Font box is grayed out, but the font "Cambria
(headings)" is preselected, and cannot be de-selected. Size is also
grayed out but not preset to any particular size. I can change the
color and font style (bold, etc.), underlining, and strikethrough.
According to an explanatory sentence in the dialog, this combination
of changeable and nonchangeable font features is the way it's supposed
to be with conditional formatting.

ANYWAY, the problem is that the preselected Cambria font is invoked
when the condition is satisfied (my worksheet font is Arial). Is
there any way to de-select Cambria?

POSSIBLE ANSWER (I worked this out while writing this post; this MAY
be the cause and it may help other users): I originally created this
worksheet with Excel 2003; shortly thereafter, the office switched to
Office 2007. Somehow, even though Cambria was not selected in Excel
2003, this preselection appeared in Excel 2007 in those cells that
were conditionally formatted in Excel 2003. Fortunately, in Excel
2007, no font is preselected in Conditional Formatting in not-
previously-conditionally-formatted cells in the worksheet, or in new
worksheets. This will be easy enough to fix.

Thanks for reading!