code hangs up on standard formatting

I have a app that runs a userform. The first time through, the
application takes about 15 seconds to execute. Any subsequent run of
the userform is instantaneous.

I traced the delay to the following code snippet. The code creates a
balloon (circle shape), inserts a number (numbers run from 1-99) from
the spreadsheet into the circle, formats it, then places it in a
specified X-Y position on another sheet. The offending code appears to
be:

With Selection.Characters(Start:=1, Length:=2).Font
.Name = "Arial"
.Size = 9
.FontStyle = "Bold"
.ColorIndex = 2
End With

Any suggestions why?

Art